Apache2: enable browser caching

a2enmod expires headers
service apache2 restart

Add the following lines to .htaccess

# Enable browser caching
<IfModule mod_expires.c>
  ExpiresActive On
  ExpiresDefault "access plus 1 month"
  ExpiresByType image/gif "access plus 1 month"
  ExpiresByType image/ico "access plus 1 month"
  ExpiresByType image/x-icon "access plus 1 year"
  ExpiresByType image/jpeg "access plus 1 month"
  ExpiresByType image/jpg "access plus 1 month"
  ExpiresByType image/png "access plus 1 month"
  ExpiresByType image/svg+xml "access plus 1 month"
  ExpiresByType text/html "access plus 1 month"
  ExpiresByType text/css "access plus 1 month"
  ExpiresByType text/javascript "access plus 1 month"
  ExpiresByType text/xml "access plus 1 month"
  ExpiresByType application/x-javascript "access plus 1 month"
  ExpiresByType application/javascript "access plus 1 month"
  ExpiresByType application/json "access plus 1 month"
  ExpiresByType application/pdf "access plus 1 month"
  ExpiresByType font/woff "access plus 1 month"
  ExpiresByType font/woff2 "access plus 1 month"
  ExpiresByType video/mp4 "access plus 1 month"
  ExpiresByType video/webm "access plus 1 month"
  <FilesMatch "\.(woff2)$">
    Header set Cache-Control "max-age=2591999, public"
  </FilesMatch>
</IfModule>