Also ran gofmt on everything. Thanks again @paralin. #334

Co-authored-by: Christian Stewart <christian@paral.in>

Co-authored-by: Anmol Sethi <hi@nhooyr.io>

When the ctx is nil, http.NewRequestWithContext returns a "net/http:
nil Context" error and a nil request. In this case, the dial function
panics because it assumes the req is never nil. This checks the
returning error and returns it, so that callers get an error instead
of a panic in that scenario.

Thank you @icholy for identifying these in
https://github.com/nhooyr/websocket/pull/259#issuecomment-702279421

HTTP header values, as opposed to header keys,
are case sensitive, but implementation of headerTokens()
before this patch would return lowered values always.

This old behavior could lead to chromium (v87) WebSocket
rejecting connnection because negotiated subprotocol,
returned in Sec-WebSocket-Protocol header (lowered
be headerToken() function) would not match one sent
by client, in case client specified value with capital
letters.

See: https://staticcheck.io/docs/checks#SA4001

Closes #220 and #230

Much simpler config. Github Actions just isn't there yet.

See https://github.com/nhooyr/websocket/issues/182

Closes #182

Too many improvements and changes to list.

Will include a detailed changelog for release.

Removes the tiny filenames polluting the root directory.

Closes #121

The docs were way too Canadian with all the pleases ^_^

The boys in the office hated it.

Highly unfortunate but makes sense as it seems confusing.

Will be cleaner in GitHub as the README.md is the first
thing you will see instead of a massive directory listing.

Closes #134

Closes #122

Closes #88