Upgrade to BS4, replace BS grid with CSS grid, remove equal heights script

[mbabker]

Title says it all.

Item 1 - Bootstrap 4 upgrade

Item 2 - Replaces the Bootstrap 3 grid with a CSS grid for the areas of the site using grids.

• Homepage "Get Involved" area
• Homepage footer area
• Contributors page

Item 3 - The grid makes the equal heights script unnecessary so that's removed.

Ping @C-Lodder and @dgt41 as I'm pretty sure even though the grid works I'm probably going to need fallbacks and that's asking too much of my PHP oriented brain 😆

[C-Lodder]

Looking forward to testing on IE11 :) (assuming that's your min support), but can't until this is sorted: https://github.com/joomla/framework.joomla.org/issues/20

[mbabker]

Looking forward to testing on IE11 :) (assuming that's you min support)

I just looked at Analytics for YTD. Frankly, supporting IE 10 and older is just crazy at this point (both because of browser age and accounting for less than .5% of all traffic).

[dgrammatiko]

@mbabker @ciar4n is working on something totally new for this site, I saw it and I'm amazed! @ciar4n bring it on 🎉

[mbabker]

Even better, this site is a prime example of why people can't build something then leave a design impaired developer to maintain things 🤣