add jekyll metadata to gitignore
add jekyll metadata to gitignore

alexjlockwood/alexjlockwood.github.io,alexjlockwood/AndroidDesignPatterns,alexjlockwood/AndroidDesignPatterns,alexjlockwood/alexjlockwood.github.io,alexjlockwood/AndroidDesignPatterns,alexjlockwood/alexjlockwood.github.io