Intelligent Build Process: Update Modified Content Only

[766F6964]

Summary:

Currently, every-time the script is executed, all blog posts are rebuilt (except the ones that have the ignore prefix).
While this is okay if the blog only has a couple of posts, the build times get pretty long when a user has hundreds of posts.
This is especially annoying if you just want to rebuild to if some of your changes look good on the page. Or if you fix a typo, and you need to wait minutes just for rebuilding. We can do better!

Suggestion:

We want to keep things simple, and not introduce a bunch of new dependencies.
All that is needed, is to create a "database", that maps the file-path of posts/pages to the hash of their content.
That way, we can check each post/page before building by looking up their hash in the database file. (If there were no changes since the last build, we don't have to rebuild the file).
This way, we would only rebuild files that got changed, increasing build times massively.
We also don't need to introduce an actual database, maybe a simple json/xml/ini file is enough. Will have to see.