*  fix redirected npmjs links
* change npm to lowercase
* use https when possible

Ported from karma-runner/karma-runner.github.com#55

This has the same result (symlink to the `karma` in the node_modules), but has two benefits:

- karma developers don't need to run extra command
- no peer dependency warnings when `npm install` is run

…3672)


Companion PR for karma-runner/karma-runner.github.com#62.

* docs: fix invalid heading syntax

It is not recognized as a heading by the markdown parser without a whitespace.

* docs: fix weird syntax to reduce diff

Old parser considered this the same list, but new parser assumes that these are two separate lists. Technically it should be a nested list, but it is old and shouldn't really matter. I'm doing this change to reduce the diff I need to review after switching to the new markdown parser.

* docs: fix invalid markdown

Items nested in the list item, must be indented 3 spaces, not 2 spaces. New parser produced a pretty messed up markup from the invalid markdown.

* docs: remove redundant whitespaces in the list items

When using the proxy feature of Karma, the target value can include the [scheme](https://tools.ietf.org/html/std66#section-3.1). It was used to determine the `https` variable to be sent to the [`http-proxy`](https://www.npmjs.com/package/http-proxy) `.createProxyServer` method. However, it is now disregarded by that package. This change cleans it up.

## [6.3.3](v6.3.2...v6.3.3) (2021-06-01)

### Bug Fixes

* **server:** clean up vestigial code from proxy ([#3640](#3640)) ([f4aeac3](f4aeac3)), closes [/tools.ietf.org/html/std66#section-3](https://github.com//tools.ietf.org/html/std66/issues/section-3)