Fix README: Add pull-requests write permission (#9)

The action posts PR comments when ENABLE_PR_COMMENTS is enabled,
which requires pull-requests: write permission. Updated:

- GitHub App permissions table to clarify Read and Write needed
- PAT description to include pull requests write access
- All workflow examples to include pull-requests: write permission
- All workflow examples to include issues: write permission

This ensures users grant the correct permissions for all features
(issue creation and PR commenting) to work properly.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: zkoppert

README.md

@@ -76,15 +76,15 @@ This action can be configured to authenticate with GitHub App Installation or Pe
 
 The required GitHub App permissions under `Repository permissions` are:
 
-- `Pull Requests` - Read (needed to scan open pull requests and their changed files)
+- `Pull Requests` - Read and Write (Read: scan open pull requests and their changed files; Write: post PR comments when `ENABLE_PR_COMMENTS` is enabled)
 - `Contents` - Read (needed to fetch file diffs and line ranges)
 - `Issues` - Read and Write (needed to create conflict report issues)
 
 ##### Personal Access Token (PAT)
 
 | field      | required | default | description                                                                                                                                              |
 | ---------- | -------- | ------- | -------------------------------------------------------------------------------------------------------------------------------------------------------- |
-| `GH_TOKEN` | True     | `""`    | The GitHub Token used to scan repositories. Must have read access to pull requests and contents, and write access to issues for all repositories in scope. |
+| `GH_TOKEN` | True     | `""`    | The GitHub Token used to scan repositories. Must have read access to pull requests and contents, and write access to issues and pull requests for all repositories in scope. |
 
 #### Other Configuration Options
 
@@ -123,6 +123,8 @@ on:
 
 permissions:
   contents: read
+  issues: write
+  pull-requests: write
 
 jobs:
   detect-conflicts:
@@ -149,6 +151,8 @@ on:
 
 permissions:
   contents: read
+  issues: write
+  pull-requests: write
 
 jobs:
   detect-conflicts:
@@ -173,6 +177,8 @@ on:
 
 permissions:
   contents: read
+  issues: write
+  pull-requests: write
 
 jobs:
   detect-conflicts:
@@ -203,6 +209,8 @@ on:
 
 permissions:
   contents: read
+  issues: write
+  pull-requests: write
 
 jobs:
   detect-conflicts: