Reorganize documentation structure and introduce developer guide (#2786)

* Reorganize documentation structure and introduce developer guide

* Reorganize documentation structure and introduce developer guide

* Add developer guide link to root README

* Fix image path in requirements.md

Author: Heller07

README.md

@@ -260,13 +260,17 @@ Most plugins should be supported out-of-the-box or maybe require some minimal ch
 
 ## Adding JCasC support to a plugin
 
-Plugin developers wanting to support JCasC in their plugin should [check out our how-to guide](docs/PLUGINS.md).
+Plugin developers wanting to support JCasC in their plugin should [check out our how-to guide](docs/developer/plugins.md).
 
 ## Configuration-as-Code extension plugins
 
 - [configuration-as-code-groovy-plugin](https://github.com/jenkinsci/configuration-as-code-groovy-plugin)\
   Allows specifying groovy code that should run on during configuration.
 
+## Developer Documentation
+
+See the [Developer Guide](docs/developer/README.md).
+
 ## Jenkins Enhancement Proposal
 
 As configuration as code is demonstrated to be a highly requested topic in the Jenkins community, we have published

docs/CONTRIBUTING.md

@@ -4,7 +4,8 @@
 
 ## Reporting plugin compatibility issues
 
-See [COMPATIBILITY](./COMPATIBILITY.md)
+See [compatibility](developer/compatibility.md)
+
 
 ## Why should you contribute
 

docs/developer/README.md

@@ -0,0 +1,12 @@
+# Developer Documentation
+
+This section contains documentation for contributors and plugin developers
+working on the Configuration as Code plugin.
+
+## Architecture & Design
+
+- [developer.md](developer.md) — Overview of the JCasC API and extension model
+- [implementation.md](implementation.md) — Internal configuration processing details
+- [plugins.md](plugins.md) — Guidance related to plugin integration
+- [requirements.md](requirements.md) — Conventions and requirements for plugin maintainers
+- [compatibility.md](compatibility.md) — Reporting and handling plugin compatibility issues

docs/COMPATIBILITY.md docs/developer/compatibility.mddocs/COMPATIBILITY.md renamed to docs/developer/compatibility.md

@@ -5,7 +5,7 @@ API, but still require plugins to respect some contract, aka "_convention over e
 This documentation is here to explain plugin maintainers those conventions and provide guidance
 on expected design.
 
-![JCasC is coming](../images/BraceYourselves.jpg)
+![JCasC is coming](../../images/BraceYourselves.jpg)
 
 ## Overview