Add PHP memory limit documentation for Docker builds

- Document --build-arg PHP_MEMORY_LIMIT option for large projects
- Default is 1024M, can increase to 2048M or more as needed
- Update Dockerfile version label to 0.0.1
- Add notes in both English and Japanese sections

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Dockerfile

@@ -2,7 +2,7 @@ FROM php:8.3-cli-alpine
 
 LABEL maintainer="Security Linter Team"
 LABEL description="PHP/Laravel Security Linter - Static security analysis tool"
-LABEL version="1.0.0"
+LABEL version="0.0.1"
 
 # Build arguments
 ARG PHP_MEMORY_LIMIT=1024M