This is a starting point to dynamically loading `markdown` files as blog
entries. With this change the *doc/about.md* and *doc/blog.md* files
are no longer builded into the executable and instead read from the
filesystem during runtime (along with the new test file *doc/test.md*).
With functional increments in `zterm`'s `Scrollable` `Element`, an
implementation (such as `Content`) can provide a size hint for the
minimal required size to dynamically change its dimensions for the
scrollable `Container` in the `Scrollable` `Element`.
Vaxis sadly cannot be used for applications which want to serve their contents via ssh to the (remote) user.
Instead I wrote my own tui library [zterm](https://gitea.yves-biener.de/yves-biener/zterm), which this tui application now uses. This will serve two purposes:
1. implement the tui application and be servable through ssh (see [wish-serve](https://gitea.yves-biener.de/yves-biener/wish-serve))
2. serve as documentation and showcase of an example application for **zterm**
Reviewed-on: #1
Not everything can be parsed and displayed correctly yet, however this
will the default file format to use for adding page contents (i.e.
normal pages, blog entries, etc.)
