docs(readme): fix readme error handling subsection

The commit removes detailed error handling subsections from the README.md to simplify documentation organisation. The removed sections included:

- Git related errors
- API key related errors
- Anthropic API errors
- Other errors

All error handling information remains available in the main Error Handling section.

Author: tsdevau

README.md

@@ -26,10 +26,6 @@ The generated commit messages are compatible with [googleapis/release-please](ht
     - [`diffCommit.maxTokens`](#diffcommitmaxtokens)
     - [`diffCommit.temperature`](#diffcommittemperature)
   - [Error Handling](#error-handling)
-    - [Git Related](#git-related)
-    - [API Key Related](#api-key-related)
-    - [Anthropic API Errors](#anthropic-api-errors)
-    - [Other Errors](#other-errors)
   - [Local Development](#local-development)
     - [Local Testing](#local-testing)
   - [Contributing](#contributing)
@@ -176,35 +172,6 @@ Diff Commit accommodates error handling to provide clear feedback and assist in
 
 If you encounter any of these errors, Diff Commit will display a message with more details. For persistent issues, please check your configuration and if appropriate, raise an issue on [GitHub](https://github.com/tsdevau/diff-commit/issues).
 
-### Git Related
-
-- Git extension not found in VSCode
-- No Git repository found in the current workspace
-- No workspace folder found
-- No staged changes detected
-
-### API Key Related
-
-- API key is missing or not provided
-- Invalid API key format (should start with sk-ant-api)
-- Failed to access or update secure storage
-
-### Anthropic API Errors
-
-- **400** - Bad Request: Review your prompt and try again
-- **401** - Unauthorized: Invalid API key, update your API key and try again
-- **403** - Forbidden: Permission denied, update your API key and try again
-- **429** - Rate Limited: Too many requests, try again later
-- **500** - Server Error: Anthropic API server error
-
-### Other Errors
-
-- Failed to write commit message to Source Control
-- Failed to open commit message preview
-- No commit message was generated by the API
-
-If you encounter any of these errors, the extension will display a message with more details. For persistent issues, please check your setup and if appropriate, raise an issue on [GitHub](https://github.com/tsdevau/diff-commit/issues).
-
 ## Local Development
 
 1. Clone the [repository](https://github.com/tsdevau/diff-commit)