Added how-to file

how_to_update_language_boundaries.txt

@@ -0,0 +1,7 @@
+(Very jank)
+1. Make changes in the code eg. changing the language of a state or district.
+2. Uncomment the snippet of code at the bottom of index.js. This is responsible for printing out the language boundaries as JSON.
+3. Get the JSON from the browser console, put it in a file, and un-minifiy it.
+4. Copy the resulting JSON's text into 'india_with_districts_with_languages.json'. Put it at the start of the file, replacing the old language boundaries.
+5. Fix any remaining errors that pop up (should be nothing major).
+	a. If Tulu and Sindhi are not loading, it's because, for some reason, the JSON definition for these languages includes the district that they're spoken in (because they're only spoken in 1 district). So the code assumes that it's a _district_, rather than a _language_ definition.