Map SVG updates: add Elkhart, remove old stations

[benlk]

Changes

This pull request makes the following changes:

• Creates new "Elkhart" region in the map, and removes references to Elkhart from the former "South Bend/Elkhart" region. Elkhart's placement on the map is based on https://en.wikipedia.org/wiki/Elkhart,_Indiana#/media/File:Elkhart_County_Indiana_Incorporated_and_Unincorporated_areas_Elkhart_Highlighted_1820728.svg
• Renames WVPE-TV to WVPE-FM and moves its labelling to Elkhart. The station's color remains the "FM" red, and the station's coverage circle does not move.
• Removes WBSJ-FM, WCKZ, and W204BF from the map.
• Adjusts the layout of labels for Fort Wayne and Muncie to clear up gaps left by the removed station

I can't upload .mov or .mp4, so here's a dithered .gif:

Why

For #87 and #88

Testing/Questions

Features that this PR affects:

• the map SVG used on the homepage

Questions that need to be answered before merging:

• Is this PR targeting the correct branch in this repository?

Steps to test this PR:

1. view the gif above, or check this out locally and interact with an instance of the IPBS Member Map widget.