godev: move static css and typescript tooling config

Currently, the css and typescript files from cmd/gotelemetry/view
are out of scope for formatters and linters installed by npm.
Moving the css and typescript config to the root of the repo fixes
this issue.


Change-Id: I1ddc40050c494a3c7c59707304fa7bf707531bee
Reviewed-on: https://go-review.googlesource.com/c/telemetry/+/524195
TryBot-Result: Gopher Robot <[email protected]>
Reviewed-by: Hyang-Ah Hana Kim <[email protected]>
Run-TryBot: Jamal Carvalho <[email protected]>

Author: jamalc

godev/.eslintignore renamed to .eslintignore

@@ -2,6 +2,47 @@
 
 This repository holds the Go Telemetry server code and libraries.
 
+## TypeScript Support
+
+TypeScript files served from content directories are transformed into
+JavaScript. Reference .ts files in html templates as module code.
+
+`<script type="module" src="/filename.ts">`
+
+## Linting & Formatting
+
+This repository uses [eslint](https://eslint.org/) to format TS files,
+[stylelint](https://stylelint.io/) to format CSS files, and
+[prettier](https://prettier.io/) to format TS, CSS, Markdown, and YAML files.
+
+See the style guides:
+
+- [TypeScript](https://google.github.io/styleguide/tsguide.html)
+- [CSS](https://go.dev/wiki/CSSStyleGuide)
+
+It is encouraged that all TS and CSS code be run through formatters before
+submitting a change. However, it is not a strict requirement enforced by CI.
+
+### Installing npm Dependencies:
+
+1. Install [docker](https://docs.docker.com/get-docker/)
+2. Run `./npm install`
+
+### Run ESLint, Stylelint, & Prettier
+
+    ./npm run all
+
+## Third Party
+
+The `third_party` directory was generated with `go run ./devtools/cmd/npmdeps`.
+It contains JS packages that are served by the web site. To add or upgrade a new
+dependency use the necessary `./npm` command then run
+`go run ./devtools/cmd/npmdeps`. Remove unnecessary files from the copy result
+where appropriate. For example, `content/localserver/index.html` only depends on
+files from `third_party/[email protected]/dist/` so the directory
+`third_party/[email protected]/src` can be deleted.
+
+
 ## Report Issues / Send Patches
 
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