feat: pmd (#89)

Author: cr-ruhanmuzaffar

docs/tools/pmd.md

@@ -0,0 +1,25 @@
+---
+title: PMD
+sidebar_label: PMD
+description: CodeRabbit's guide to PMD.
+---
+
+[PMD](https://pmd.github.io/) is an extensible multilanguage static code analyzer. It’s mainly concerned with Java.
+
+## Files
+
+PMD will run on files with the following extensions:
+
+- `.java`
+
+## Configuration
+
+PMD uses an XML configuration file.
+
+PMD supports the following config files:
+
+- User-defined config file set at `reviews.tools.pmd.config_file` in your project's `.coderabbit.yaml` file or setting the "Review → Tools → PMD → Config File" field in CodeRabbit's settings page.
+
+## Links
+
+- [PMD Configuring rules](https://pmd.github.io/pmd/pmd_userdocs_configuring_rules.html)

docs/tools/tools.md

@@ -53,6 +53,7 @@ Remove extraneous f prefix
 | Markdown                    | [Markdownlint][Markdownlint], [LanguageTool][LanguageTool] |
 | PHP                         | [PHPStan][PHPStan]                                         |
 | Plaintext                   | [LanguageTool][LanguageTool]                               |
+| PMD                         | [PMD][PMD]                               |
 | Protobuf                    | [Buf][Buf]                                                 |
 | Python                      | [Ruff][Ruff]                                               |
 | Regal                       | [Regal][Regal]                                             |
@@ -81,3 +82,4 @@ Remove extraneous f prefix
 [Buf]: ./buf.md
 [Actionlint]: ./actionlint.md
 [Regal]: ./regal.md
+[PMD]: ./pmd.md