Merging the HOW-TOs inside the FAQ allows to have a central place to
look for information. It will also offer all HOW-TOs through the
`SPC f e h` helm search.
This commit apply the following changes:
- Remove leading whitespaces
- Apply fill-paragraph to justify answers' paragraphs.
- Add question: how to define/change an evil-leader prefix?
- Add question: user-init or user-config?
Add a release note about the limitation of org loading since 0.105, and
also document it in the org-layer's README.
Close#3277
Move note to FAQ and correct text to 0.104