Ref. PG02-1

Is your feature request related to a problem? Please describe.
As an administrator I want to be able to highlight any relevant content within the process group (a participatory process, a meeting, a debate, a proposal gathering process, a page, etc ...)
I've also want a way for adding one/two/three blocks inline with image/title/subtitle/link and i18n support.

Describe the solution you'd like
To have the possiblity to have multiple HTML blocks on the content blocks. These would be similar to the current HTML block that we have for the homepage (with i18n support) but with one caveat: it should be possible to add multiple (as in more than one block).

Note that for uploading this images for using the HTML there are a couple solutions although are not so pretty (hack):

1. to upload it to the app code (app/assets/images)
2. to upload it through a current file upload:
   2.1) save the current file image
   2.2) upload the one that you want
   2.3) copy the URL
   2.4) upload the saved image from 2.1)

Describe alternatives you've considered
To add to the main page of a given process group (ie on /processes_groups/X) an optional section of secondary highlights with 1, 2 or 3 highlights aligned with an image, a title and a CTA button. This should be based at least on the main idea with the Content Blocks as we have them implemented in the Homepage (Hero, Banner, etc)
To have three possible blocks for an admin to choose, or three different dessigns that change on the different contents that we already have.

Additional context

We're using this feature for the current homepage of Decidim Barcelona:

Does this issue could impact on users private data?
No

Acceptance criteria

• As an administrator I can add one HTML block in PG landing
• As an administrator I can add two HTML block in PG landing
• As an administrator I can add three HTML block in PG landing
• As an administrator I can have different HTML contents for every active language