* adds `npm start` / `yarn start` script
* starts a webpack-dev-server using the dev config, served on :3333
* hot reloading (HMR) for react/styles, not working for angular code
* new entry `dev.ts` for dynamic imports of CSS theme (ExtractText does
not work with HMR)
* TS loader pipeline moved out of common to add HMR for react
* applied `hot()` to some react containers (that's their new default
 export, named exports remains for testing)
* added sections to README
* updated yarn.lock

Removes alpha 

closes https://github.com/grafana/grafana/issues/11251

In "Install from source" section supposed that Grafana`s sources installed to `~/go` , but it is not always true. 
In other hand, `go get ..` command would install project to `$GOPATH`

https://golang.org/cmd/go/#hdr-Download_and_install_packages_and_dependencies

[skip ci]

[skip ci]

Simplified build instructions i

* tech: investigating karma + jest mix

* tech: migrating tests to jest

* tech: moved anoter test file to jest

* test: migrated two more test files to jest

* test: updated readme and made test fail to verify that it causes CI build failure

* tech: added code coverage for jest tests

* tech: testing codecov coverage

* tech: migrated more tests

* tech: migrated template srv to typescript and the tests to jest

* tech: minor build fix

* tech: build fixes

* build: another attempt at fixing go test with coverage

* webpack poc, this is not going to work for plugins, dam

* tech: webpack and systemjs for plugins starting to work

* tech: webpack and systemjs combo starting to work

* tech: webpack + karma tests progress

* tech: webpack + karma progress

* tech: working on tests

* tech: webpack

* tech: webpack + karma, all tests pass

* tech: webpack + karma, all tests pass

* tech: webpack all tests pass

* webpack: getting closer

* tech: webpack progress

* webpack: further build refinements

* webpack: ng annotate fixes

* webpack: optimized build fix

* tech: minor fix for elasticsearch

* tech: webpack + ace editor

* tech: restored lodash move mixin compatability

* tech: added enzyme react test and upgraded to react v16

* tech: package version fix

* tech: added testdata to built in bundle

* webpack: sass progress

* tech: prod & dev build is working for the sass

* tech: clean up unused grunt stuff and moved to scripts folder

* tech: added vendor and manifest chunks, updated readme and docs

* tech: webpack finishing touches

remove dev.ini reference as it seems not working anymore.

* tech(build): replace npm with yarn

* tech(build): change node version for CI