Improve build script

[jamestalmage]

This ads a ./run.sh script that is a wrapper for the wikidata update.sh scripts, but it has a much simpler call signature. No more remembering if it needs to be called with uppercase, etc.

./run.sh fetch_write admin_0_countries # fetch_write the countries file at 10m, 50m, and 110m zoom levels


./run.sh fetch 10m_0_countries # fetch the countries file at 10m
./run.sh fetch ne_10m_countries # equivalent to the above

./run.sh fetch 10m # fetch all the 10m files
./run.sh fetch 10m_physical # fetch all the 10m_physical files

[nvkelso]

Hey @jamestalmage, thanks for all your recent activity in this repo! I'm recently returned from traveling and will look at your PRs and issues soon.