Add \cvtag support with item tags

[gouvinb]

Proposal

Summary and problem statement

Currently "\cvtag" is supported through a latex block, like this:

* Strengths

#+BEGIN_EXPORT latex
\cvtag{Hard-working}
#+END_EXPORT

The objective of this project being to make a CV in pure org format, \cvtag must be supported in a more adapted format.

Motivation, use-cases, and solution sketches

There are 3 points to consider for this feature:

1. The cvtag name should be a item list.
2. Add newline support

Design proposals

* Strengths

- tag 1 :: \\
- tag n ::