Fix: various adjustments

[Alessandro100]

Summary:

Various small adjustments in the Web-App

Sign-In page

• Button hover styling fix

Feed Detail page

• Bug fix: tld-823 blank fix (null / undefined check)
• Button usability fix (better clicking)

Home page

• text update: 2000 -> 3000 feeds

Feeds search page

• Feature filter is now default closed
• Search bar is now sticky when scrolling down
• Bug fix: selecting features / data type and clicking "back" in browser

General

• Added description to website

Expected behavior:

On feeds page when scrolling down the search bar should be sticky. Also back navigation when feature selecting should be working as well

Testing tips:

1. Go to tld feeds ex feeds/tld-823 and see the page working
2. Test out feeds page url navigation + clicking back
3. On feeds page scroll down and make sure search bar sticks

Please make sure these boxes are checked before submitting your pull request - thanks!

• Run the unit tests with ./scripts/api-tests.sh to make sure you didn't break anything
• Add or update any needed documentation to the repo
• Format the title like "feat: [new feature short description]". Title must follow the Conventional Commit Specification(https://www.conventionalcommits.org/en/v1.0.0/).
• Linked all relevant issues
• Include screenshot(s) showing how this pull request works and fixes the issue(s)

[github-actions]

Preview Firebase Hosting URL: https://mobility-feeds-dev--pr-855-ejk2938k.web.app

[davidgamez]

[question]: Are we planning, at some point, to have most of these style changes in a CSS/theme location?

[Alessandro100]

yes I will explore this in my style POC side car. To determine what should go in the theme and what should be a style local to the component, and how we organize these styles

[davidgamez]

LGTM!