Correct quoting/code block of documentation for 'salt.states.reg.present()'.
Merge pull request #12769 from eliasp/states-reg_doc-fix

Correct quoting/code block of documentation for 'salt.states.reg.present()'
Correct code-block usage.
Correct usage of 'CLI Example' in documentation blocks

This mass-edit was done using the following shell command:
ack -l '^(\s*)CLI Example::$' \
| xargs sed -i \
's/^\(\s*\)CLI Example::/\1CLI Example:\n\n\1.. code-block:: bash/g'