Optimization PR#1 - Featured competitions

[ihsaan-ullah]

@ mention of reviewers

@Didayolo

A brief description of the purpose of the changes contained in this PR.

• is_featured field added in competition modal (default = False)
• This field is now used to show featured competitions on the home page

NOTE: participants count is still missing here, that will be handled by PR#2

How to make a competition featured?

There are two ways to do it

1. User Django admin -> click the competition -> scroll down to is featured filed -> Check/Uncheck it
2. Use competition id in the django bash to feature/unfeature a competitions

docker compose exec django ./manage.py shell_plus
>>> comp = Competition.objects.get(id=<ID>)  # replace <ID> with competition id
>>> comp.is_featured = True  # set to False if you want to unfeature a competition
>>> comp.save()

Issues this PR resolves

• Performance problem - Pages are too slow to load #1327 -> Featured Competitions on home page

Checklist

• Code review by me
• Hand tested by me
• I'm proud of my work
• Code review by reviewer
• Hand tested by reviewer
• CircleCi tests are passing
• Ready to merge

[Didayolo]

I guess it makes sense that featured competitions are manually selected. We need to remember to update it regularly.