Remove Webpack config and try test build

[markerikson]

This PR:

• Removes the 'T' prefix from all generic args for simplicity
• Documents the type overloads for dispatch
• Removes the dead Webpack config file
• Adds a typetest to cover [TypeScript] Generic action creators fail to resolve through ThunkDispatch overloads #248 and #248 Add union overload to ThunkDispatch #255

and actually gets CodeSandbox CI running so we have test builds

[codesandbox-ci]

This pull request is automatically built and testable in CodeSandbox.

To see build info of the built libraries, click here or the icon next to each commit SHA.

Latest deployment of this branch, based on commit 1677f1e:

Sandbox	Source
Vanilla	Configuration
Vanilla Typescript	Configuration