chore: add copyright headers

Make sure we obey the REUSE (https://reuse.software) specification and the
origin, copyright owner, and license of all files are clearly marked.

The whole project is under the EPL-2.0, except for trivial files where copyright
is not applicable that are marked with the CC0-1.0 license. Moreover, code
included from third parties is also available under the respective license.

chore: add CONTRIBUTORS.md

List all authors and supporting organizations in accordance with the REUSE
specification.

9 files changed, 49 insertions, 0 deletions

diff --git a/subprojects/language-ide/build.gradle.kts b/subprojects/language-ide/build.gradle.kts
index f996c00d..ff8630f9 100644
--- a/subprojects/language-ide/build.gradle.kts
+++ b/subprojects/language-ide/build.gradle.kts
@@ -1,3 +1,9 @@
+/*
+ * SPDX-FileCopyrightText: 2021-2023 The Refinery Authors <https://refinery.tools/>
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
+
 plugins {
         id("tools.refinery.gradle.java-library")
         id("tools.refinery.gradle.xtext-generated")
diff --git a/subprojects/language-ide/src/main/java/tools/refinery/language/ide/ProblemIdeModule.java b/subprojects/language-ide/src/main/java/tools/refinery/language/ide/ProblemIdeModule.java
index fb620065..122fe874 100644
--- a/subprojects/language-ide/src/main/java/tools/refinery/language/ide/ProblemIdeModule.java
+++ b/subprojects/language-ide/src/main/java/tools/refinery/language/ide/ProblemIdeModule.java
@@ -1,4 +1,10 @@
 /*
+ * SPDX-FileCopyrightText: 2021-2023 The Refinery Authors <https://refinery.tools/>
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
+
+/*
  * generated by Xtext 2.25.0
  */
 package tools.refinery.language.ide;
diff --git a/subprojects/language-ide/src/main/java/tools/refinery/language/ide/ProblemIdeSetup.java b/subprojects/language-ide/src/main/java/tools/refinery/language/ide/ProblemIdeSetup.java
index 5b88d41f..9d77e022 100644
--- a/subprojects/language-ide/src/main/java/tools/refinery/language/ide/ProblemIdeSetup.java
+++ b/subprojects/language-ide/src/main/java/tools/refinery/language/ide/ProblemIdeSetup.java
@@ -1,4 +1,10 @@
 /*
+ * SPDX-FileCopyrightText: 2021-2023 The Refinery Authors <https://refinery.tools/>
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
+
+/*
  * generated by Xtext 2.25.0
  */
 package tools.refinery.language.ide;
diff --git a/subprojects/language-ide/src/main/java/tools/refinery/language/ide/contentassist/FuzzyMatcher.java b/subprojects/language-ide/src/main/java/tools/refinery/language/ide/contentassist/FuzzyMatcher.java
index fe722ca1..4511223b 100644
--- a/subprojects/language-ide/src/main/java/tools/refinery/language/ide/contentassist/FuzzyMatcher.java
+++ b/subprojects/language-ide/src/main/java/tools/refinery/language/ide/contentassist/FuzzyMatcher.java
@@ -1,3 +1,8 @@
+/*
+ * SPDX-FileCopyrightText: 2021-2023 The Refinery Authors <https://refinery.tools/>
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
 package tools.refinery.language.ide.contentassist;
 
 import org.eclipse.xtext.ide.editor.contentassist.IPrefixMatcher;
diff --git a/subprojects/language-ide/src/main/java/tools/refinery/language/ide/contentassist/ProblemCrossrefProposalProvider.java b/subprojects/language-ide/src/main/java/tools/refinery/language/ide/contentassist/ProblemCrossrefProposalProvider.java
index 8f04ed00..e194ee31 100644
--- a/subprojects/language-ide/src/main/java/tools/refinery/language/ide/contentassist/ProblemCrossrefProposalProvider.java
+++ b/subprojects/language-ide/src/main/java/tools/refinery/language/ide/contentassist/ProblemCrossrefProposalProvider.java
@@ -1,3 +1,8 @@
+/*
+ * SPDX-FileCopyrightText: 2021-2023 The Refinery Authors <https://refinery.tools/>
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
 package tools.refinery.language.ide.contentassist;
 
 import java.util.Objects;
diff --git a/subprojects/language-ide/src/main/java/tools/refinery/language/ide/contentassist/TokenSourceInjectingPartialProblemContentAssistParser.java b/subprojects/language-ide/src/main/java/tools/refinery/language/ide/contentassist/TokenSourceInjectingPartialProblemContentAssistParser.java
index 3ece6f67..146bd8da 100644
--- a/subprojects/language-ide/src/main/java/tools/refinery/language/ide/contentassist/TokenSourceInjectingPartialProblemContentAssistParser.java
+++ b/subprojects/language-ide/src/main/java/tools/refinery/language/ide/contentassist/TokenSourceInjectingPartialProblemContentAssistParser.java
@@ -1,3 +1,8 @@
+/*
+ * SPDX-FileCopyrightText: 2021-2023 The Refinery Authors <https://refinery.tools/>
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
 package tools.refinery.language.ide.contentassist;
 
 import com.google.inject.Inject;
diff --git a/subprojects/language-ide/src/main/java/tools/refinery/language/ide/contentassist/TokenSourceInjectingProblemParser.java b/subprojects/language-ide/src/main/java/tools/refinery/language/ide/contentassist/TokenSourceInjectingProblemParser.java
index 80dfee5c..f906d881 100644
--- a/subprojects/language-ide/src/main/java/tools/refinery/language/ide/contentassist/TokenSourceInjectingProblemParser.java
+++ b/subprojects/language-ide/src/main/java/tools/refinery/language/ide/contentassist/TokenSourceInjectingProblemParser.java
@@ -1,3 +1,8 @@
+/*
+ * SPDX-FileCopyrightText: 2021-2023 The Refinery Authors <https://refinery.tools/>
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
 package tools.refinery.language.ide.contentassist;
 
 import com.google.inject.Inject;
diff --git a/subprojects/language-ide/src/main/java/tools/refinery/language/ide/contentassist/antlr/ProblemTokenSource.java b/subprojects/language-ide/src/main/java/tools/refinery/language/ide/contentassist/antlr/ProblemTokenSource.java
index c6c7f41f..fdc17c4f 100644
--- a/subprojects/language-ide/src/main/java/tools/refinery/language/ide/contentassist/antlr/ProblemTokenSource.java
+++ b/subprojects/language-ide/src/main/java/tools/refinery/language/ide/contentassist/antlr/ProblemTokenSource.java
@@ -1,4 +1,10 @@
 /*
+ * SPDX-FileCopyrightText: 2021-2023 The Refinery Authors <https://refinery.tools/>
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
+
+/*
  * generated by Xtext 2.29.0.M2
  */
 package tools.refinery.language.ide.contentassist.antlr;
diff --git a/subprojects/language-ide/src/main/java/tools/refinery/language/ide/syntaxcoloring/ProblemSemanticHighlightingCalculator.java b/subprojects/language-ide/src/main/java/tools/refinery/language/ide/syntaxcoloring/ProblemSemanticHighlightingCalculator.java
index 7703e4e3..e8f97d51 100644
--- a/subprojects/language-ide/src/main/java/tools/refinery/language/ide/syntaxcoloring/ProblemSemanticHighlightingCalculator.java
+++ b/subprojects/language-ide/src/main/java/tools/refinery/language/ide/syntaxcoloring/ProblemSemanticHighlightingCalculator.java
@@ -1,3 +1,8 @@
+/*
+ * SPDX-FileCopyrightText: 2021-2023 The Refinery Authors <https://refinery.tools/>
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
 package tools.refinery.language.ide.syntaxcoloring;
 
 import com.google.common.collect.ImmutableList;