Tags: RedGridTactical/RedGridMGRS

docs: Android is live on Google Play

- README: replace "Coming Soon" Google Play badge with live Download link
- README: Install > Android now points to the live Play Store listing
- README: roadmap entry for v3.3.2 headlines the Android launch
- Remove residual "Android in closed testing" / "Android launch planned" copy
- docs/index.html: add Google Play CTA button in the hero, Google Play
  link in the footer, Android to the structured-data operatingSystem
- Update FAQ entry from "when is Android coming?" to an affirmative
  "Yes, Red Grid MGRS is on Android" pointing at the Play Store

v2.0: Add Pro IAP, waypoint lists, extra templates, themes, coord for…

…mats