This commit removes any logic in the app and in specs around
enable_experimental_hashtag_autocomplete and deletes some
old category hashtag code that is no longer necessary.
It also adds a `slug_ref` category instance method, which
will generate a reference like `parent:child` for a category,
with an optional depth, which hashtags use. Also refactors
PostRevisor which was using CategoryHashtagDataSource directly
which is a no-no.
Deletes the old hashtag markdown rule as well.
Added in c2013865d7,
this migration was supposed to only turn off the hashtag
setting for existing sites (since that was the old default)
but its doing it for new ones too because we run all migrations
on new sites.
Instead, we should only run this if the first migration was
only just created, meaning its a new site.
It's very easy to forget to add `require 'rails_helper'` at the top of every core/plugin spec file, and omissions can cause some very confusing/sporadic errors.
By setting this flag in `.rspec`, we can remove the need for `require 'rails_helper'` entirely.
Allows to write custom code blocks:
```
```mermaid height=200,foo=bar
test
```
```
Which will then get converted to:
```
<pre data-code-wrap="mermaid" data-code-height="200" data-code-foo="bar">
<code class="lang-nohighlight">
test
</code>
</pre>
```
New site settings:
enable_markdown_linkify: which is default on, auto links https:// and http:// and mail://
markdown_linkify_tlds: which allows control of what tlds get autolinked for cases such as www.site.com, default is com|net|gov
