This commit
* removes deprecated guidelines for static file and assets struture;
* fixes some typo and mistakes;
* correctly links JS guidelines section;
* adds a running example to ease understanding;
* adds missing section about security files;
* adds text blocks for each directory to show directly the
expected result of each section;
* perform some rewording;
Thanks to @pedrobaeza for its review.
Task-1817988
jem-odoo
dadec538bc