new: [website] Add new fields to User model

[cedricbonhomme]

new: [website] Add new fields to User model: country_code, bio, webpage, mastodon, github, and linkedin

• The country_code (Alpha-3) is automatically detected during user sign-up using the CIRCL MMDB service: ip.circl.lu.
• Users can manually update their country code via the profile edit page.
• The new bio field supports Markdown format, with a Markdown editor available on the profile edit page.
• For the web profiles of the user, the property rel="me" is used on the profile view page.
• Added more validation to the various attributes of the User model.

Or course, there is a database migration.

Examples

[cedricbonhomme]

New version of the profile page with badge for Top contributors

[cedricbonhomme]

75ee913 adds a function to back up the database using pg_dump. This function is automatically triggered by the project's update command, ensuring a backup is created before any database upgrades take place. Consequently the update command has been slightly updated (you will have to restart it when updating).