readme has instructions on how to set up minkeykapp from scratch

- [ ] readme lists which symlinks to create (.minrc and .min_symbols and optionally .min_full_history)
- [ ] readme specifies version 1.2.x of nimlang needed for minlang
- [ ] readme specifies need to create .local/share/keykapp directory and start temp-cached-frequent-bigrams.json with `[]`