fix list syntax
let title underline match the headline's length
change code block name from yml to yaml
code block directives must precede a blank line
it's not possible to use placeholders in json code blocks
use caution and note directives instead of using custom markups
by default, inlined PHP code can't be rendered properly
use valid code block names so that the matching syntax highlighting is used
fix the indentation to properly render an ordered list
Merge branch 'markup-tweaks' of github.com:xabbuh/documentation into xabbuh-markup-tweaks

Conflicts:
	community/documentation.rst
Merge branch 'master' of github.com:orocrm/documentation