Move docs to src/docs

- Update the ToC and header levels of documentation

Author: rainboyan

.github/workflows/docs.yml

@@ -4,7 +4,7 @@ on:
     branches:
       - 2023.3.x
     paths:
-      - 'docs/**'
+      - 'src/docs/**'
 jobs:
   # Build job
   build:

build.gradle

@@ -303,5 +303,5 @@ tasks.withType(Groovydoc) {
 
 docs {
     dependsOn groovydoc
-    sourceDir = project.file('docs')
+    sourceDir = project.file('src/docs')
 }