42 heatmap filter

[vnoelifant]

Summary of changes:

• Normalized data so that the intensity colors made more sense (i.e. Red means more funding is needed for bigger weight, blue means lesser funding needed for lower weight).
• Also implemented most feedback from PR #41. Would like to add https://github.com/vnoelifant/charity-finder/pull/41#discussion_r1116976879 in the agenda if I can't figure that out.
• Fourth image shows error where cannot open url from embed HTML code (But it does open on a different tab).
• Worked on #42 but maybe would like to display map based on user-selected region, rather than just showing one Region.

[bbelderbos]

Nice work, the site looks amazing in those screenshots!