Plover-local-env-var

- Make module level exports explicit

**Full Changelog**: https://github.com/paulfioravanti/plover-local-env-var/compare/v0.2.4...v0.2.5

- Refactor some code
- Update types and add typechecking

**Full Changelog**: https://github.com/paulfioravanti/plover-local-env-var/compare/v0.2.3...v0.2.4

- Move config-related functionality into its own module

**Full Changelog**: https://github.com/paulfioravanti/plover-local-env-var/compare/v0.2.2...v0.2.3

- Give JSON config output some indentation to make it more readable

**Full Changelog**: https://github.com/paulfioravanti/plover-local-env-var/compare/v0.2.1...v0.2.2

- Fix reintroduced bug around fetching SHELL environment variable

**Full Changelog**: https://github.com/paulfioravanti/plover-local-env-var/compare/v0.2.0...v0.2.1

- Read in and cache known env var values from a config file when Plover starts.
- Add any added env vars to the config file so they get read in when Plover starts.
- Auto-remove any env vars with blank values from config

**Full Changelog**: https://github.com/paulfioravanti/plover-local-env-var/compare/v0.1.2...v0.2.0