With this PR we can (among actually creating taxonomies and terms) assign and remove terms from a post with the following
```php
$post = new Post(123);
$term = new Term(321);
```
Add a term to a post:
```php
$post->add_term($term);
```
Remove a term from a post:
```php
$post->remove_term($term);
```
Reviewed-on: https://codeberg.org/vlw/wp/pulls/6
This PR fixes instancing issues with `Database` due to not being able to locate its parent class from the scaffolding library. This is definitely kind of strange and should probably be investigated further. It might be because we're not autoloading these files from the library itself.
We also remove loading of Database credentials from `.env.ini` as that does not make any sense for a bundled library. Database credentials are now provided to the constructor of the `Database` class.
Reviewed-on: https://codeberg.org/vlw/wp/pulls/1
