Make podcast more accessible

[rmarquis]

The podcast is only available on the landing page, in the form of a closable top banner. If the banner is closed, it's not available anymore, unless cookies are cleared or the page opened in an incognitop window.

Including HTML widget in regular markdown pages (on the page "Concept" for example) i snot easily possible.
One easy workaround is to force the banner to be always visible, by removing the option to close it.

[leonardcser]

Possibly add this to the html layout of the page instead of a banner in docs/overrides