docs: add comprehensive guides (performance, security, configuration, testing) and error-handling example

Complete missing documentation files instead of ignoring broken links:

Added Guides:
- docs/guides/performance.md: Performance tuning, rate limiting, caching, batch operations
- docs/guides/security.md: API key management, secure configuration, data protection
- docs/guides/configuration.md: Environment-specific setup, retry/rate limit config
- docs/guides/testing.md: Unit, integration, E2E testing strategies with MSW

Added Examples:
- examples/error-handling.ts: Comprehensive error handling patterns (retry logic, circuit breaker, recovery strategies)

Updated:
- .markdown-link-check.json: Remove ignore patterns for created files

All documentation complete with working code examples and best practices.

Author: salacoste

.markdown-link-check.json

@@ -15,26 +15,11 @@
     {
       "pattern": "^https://.*\\.github.io/"
     },
-    {
-      "pattern": "^docs/guides/performance.md$"
-    },
-    {
-      "pattern": "^docs/guides/security.md$"
-    },
-    {
-      "pattern": "^docs/guides/configuration.md$"
-    },
-    {
-      "pattern": "^docs/guides/testing.md$"
-    },
     {
       "pattern": "^docs/faq.md$"
     },
     {
       "pattern": "^intermediate/error-handling.md$"
-    },
-    {
-      "pattern": "^\\./examples/error-handling.ts$"
     }
   ],
   "timeout": "10s",