Compiles css framework from sass (#1956)

* Compiles css framework from sass

* Adds watch commands

* Copies existing css to sass file

* Moves sass out of static path

* Removes global linter

I wasn't sure how to customize this, and it's not providing a lot of
additional value on top of the domain-specific linters

* Reverts invalid change to dockerfile

* Changes stylelint path

* Remove unused bulma files

* Properly minifies generated css

* Fixes regression in thread display

* rgba function only works with percents for whatever reason

* Hush stylelint

* Removes trailing zeros

* Compile sass in Django

Co-authored-by: Joachim <joachim.robert@protonmail.com>

* Python formatting

* Updates linter

* Updates commands

* Adds css-config file

Co-authored-by: Joachim <joachim.robert@protonmail.com>

* Stylelint fix

* Removes unused compiled bulma files

Co-authored-by: Joachim <joachim.robert@protonmail.com>

bookwyrm/static/css/vendor/bulma/sass/utilities/extends.sass

@@ -0,0 +1,25 @@
+@import "mixins"
+
+%control
+  +control
+
+%unselectable
+  +unselectable
+
+%arrow
+  +arrow
+
+%block
+  +block
+
+%delete
+  +delete
+
+%loader
+  +loader
+
+%overlay
+  +overlay
+
+%reset
+  +reset