Fix typo

explictly seems like a typo for explicitly

 - babel-preset-react-app@5.0.4
 - confusing-browser-globals@1.0.4
 - create-react-app@2.0.4
 - eslint-config-react-app@3.0.4
 - react-dev-utils@6.0.5
 - react-error-overlay@5.0.5
 - react-scripts@2.0.5

* Added note on update to .flowconfig for .scss imports

Added a note aimed at Flow users on how to get Flow to recognize the .scss imports.

* Mentioned .sass extension in note, added backticks

Current instructions for running using HTTPS in a PowerShell prompt are incorrect and do not work on Windows 10 v1809

* Fix click-to-open on Windows

* Oops

* use the correct dependency for babel-plugin-dynamic-import-node

* Update package.json

Update peer dependency versions in README.

Add some front page content

Tweaks 

- Copy edits for consistency
- Remove <br>'s for readability

Should all headers be Title Case? I see `Creating an App` but `Installing A Dependency`. I tend to use https://titlecaseconverter.com/, thoughts? 

Rename to match page "About The Docs"

These seem redundant, consider just "Getting Started"? Add more links?

Potpourri

* Speed up installs with pnp

* Move to a better relative path test

* Continue work on new test organization

* Move mjs test to new enhanced tests

* Move over last legacy test

* Update behavior e2e script

* Add first iteration of instructions to test readme

* Add some more bad instructions

* Split test command into multiple lines

* Use two workers (do not run in band)

* Bump install timeout

* No global pollution

* Fix PnP support via standard run mechanism

* Prevent circular serve command

* Silent yarn execs

* Fix common commands by using a shell

* Run with npx instead of Yarn

* Remove unused scripts

* Wait for localhost and fix script booting with PnP

* Don't pnp locally because links will cause module resolution to whine

* lint-staged is annoying

* Strip Yarn out of execa runs

* Set default license if none specified

* Don't impose worker limit

* Disable pnp for webpack messages

* Add missing dep...