- introduce proper approach to retrieve tag before a given tag

- add configuration options for
  - path
  - configuration
  - fromTag, toTag
  - token
- allow to specify transformers to adjust information to a specific form
- allow to specify different templates
- speed up by limiting information to pull
- add logic to automatically resolve current
- use github actions logger

src/configuration.ts

@@ -0,0 +1,27 @@
+interface Configuration {
+    sort: string;
+    template: string;
+    pr_template: string;
+    empty_template: string;
+    categories: Array<Category>;
+    transformers: Array<Transformer>;
+}
+
+interface Category {
+    title: string;
+    labels: Array<string>;
+}
+
+interface Transformer {
+    pattern: string;
+    target: string;
+}
+
+const DefaultConfiguration: Configuration = {
+    sort: "ASC",
+    template: "${{CHANGELOG}}",
+    pr_template: "- ${{TITLE}}\n   - PR: #${{NUMBER}}",
+    empty_template: "- no changes",
+    categories: [],
+    transformers: []
+}