add transitions for hover over elements

[jadx2]

For this branch I used hover transitions in 3 components:

• The subscribe button in the navbar has a hover that changes the background color to the red-danger one.
• The title links in the top story, featured stories, and sponsored insight have a hover transition animated underline.
• The last ones are the buttons with class btn-danger, used for the forms and subscribe section, have a hover with an increased scale.
  All of these animations are just for the desktop version of the webpage.

[jpdf00]

Used all the lessons on the code.
descriptive and professional pull request.
No linters errors.
Meaningful commits.

Excellent and professional work.