[Outreachy Task Submission]: Browser font size settings does not reflect in site

[mannyAndem]

Problem

Most of the font sizes in the platform code is coded in pixels. This is bad because browser font size settings does
not affect the font sizes of text in the site. In other words, bad accessibility. Users with low vision may not be able to read text clearly and would appreciate their font size preferences being respected.

Fix

Fixing this would require creating a base font sass variable to hold the font size in rem then create other variables as required that get their final computed size by multiplying the base font size by some number value. While just rewriting the font sizes to rem would fix the issue, the variable approach would allow for consistent sizing across the application.

[mannyAndem]

Fixed the issue and submitted a pr :)

@Angamanga could you have a look?