Tag to menu item organisation automation

This was a simple change to the crankthecode website. It is a backend change but it makes my life easier.

Basically, to summarise, I have made the code use the tags in blog and non-blog posts to automatically match their menu item counterparts in the UI.

To do this I created a tagging system, slightly enhancing what I had already with a prefix of 'cat:' for a category. e.g. 'cat:blog' or 'cat:Tools' which is case insensitive; though the left menu items on the front page of the UI remain correctly cased.

This means I can simply post new markdown files as I choose without any additional coding friction going forward.

The 'All posts' menu item still excludes blog posts by default but I have added a specific blog posts toggle button in case a viewer wants full visibility.

Lastly, I have added a UI enhancement that only displays the 1st five posts by default once you click through from any menu item on the landing page. There is a 'More...' button to expand for more posts.

No more hassle updating HTML files.

JOY!

-A nice tidy refactoring upgrade.