Highlight CQL and other new languages, and refresh the highlighting theme - #213

- Register highlightjs-cql 1.0.0 for cql and cqlsh blocks, replacing the SQL
  stand-in. It colors CQL by role (types, names, setting names, functions,
  bind markers, cqlsh prompts and commands) for Apache Cassandra, DSE, HCD,
  and Astra DB.
- Register GraphQL (graphql, gql), ported from highlight.js 11.12.0, which
  highlight.js 9 lacks. Output matches highlight.js 11 on all 19 GraphQL
  blocks in the docs.
- Add a license notice for the bundled highlighting code to the top of
  highlight.bundle.js.
- Style placeholders (<keyspace_name>) in italics instead of the error color.
- Keep lint and format off src/js/vendor/languages, which holds grammars
  maintained elsewhere.

- Give each kind of token its own color: keywords purple, types cyan,
  functions and headings pink, keys and setting names indigo, strings green,
  numbers and literals orange, variables and placeholders amber, prompts and
  comments gray, deleted lines red.
- Meet WCAG AA contrast (4.5:1) in both themes. The colors come from new
  --ds-code-* variables: shade 700 of each palette family in the light theme
  and shade 400 in the dark theme. Before, strings, numbers, types, literals,
  and function names were below 4.5:1 in the light theme (as low as 3.41:1),
  and variables and XML names were below it in the dark theme (3.96:1).
- Stop using the error color for variables and markup, and stop coloring
  whole parameter lists.
- Italicize comments. Placeholders stay italic.
- Make cqlsh prompts unselectable, like console prompts.

Setting names (such as REPLICATION in WITH REPLICATION = ...) were indigo,
next to purple keywords: a color difference (CIEDE2000) of only 8.9 in the
light theme, and harder still to tell apart in capital letters. They are
now cyan, a difference of 28.9. Types and built-ins move from cyan to lime,
which also keeps them far from the keywords they sit beside (TEXT PRIMARY
KEY). Both colors still meet WCAG AA contrast in both themes.

The preview's code page had one CQL block and no GraphQL, YAML, or XML,
so a reviewer of the UI preview couldn't see most of what this branch
changes. Add a "Syntax highlighting samples" section with CQL statements,
a CQL syntax summary with placeholders, a cqlsh session, GraphQL, YAML,
and XML. Preview pages aren't part of the UI bundle.

IBM Docs, where these docs are moving, reads the language name exactly
as written, so a block labeled [source,language-cql] isn't highlighted
there. Normalizing the label here would hide that problem from writers.
Without the normalization, such blocks are plain on this site too, which
shows that the label needs fixing.

Protobuf highlighting, added in the same earlier commit, stays.

The vendor scripts were meant to be minified, all except floatingui.js,
but a misplaced parenthesis made the build skip all of them. Minify them
as intended, with a per-file condition.

- Minifying drops the license notices from the highlight.js bundle, which
  its BSD license requires us to keep. Record each bundle's /*! ... */
  notices before minifying and put back any that are lost.
- The zooming and Floating UI bundles carried no license notice at all,
  though their MIT licenses ask for one. Add one to each.
- A first visit now downloads 88 KB of these scripts compressed, instead
  of 113 KB. The highlight.js bundle drops from 56 KB to 35 KB.

This brings in the change from the powershell-highlighting branch.

- Register highlight.js's PowerShell grammar, which also answers to ps
  and ps1. The Astra CLI's Windows instructions and the C# driver's
  NuGet commands are PowerShell, now labeled shell and cs; relabeled,
  they'll be highlighted here and on IBM Docs.
- Stop registering the INI grammar a second time as toml. The INI
  grammar already answers to toml.
- Add a PowerShell sample to the UI preview, since no page labels
  a block powershell yet.

Match highlightjs-cql's dist/cql.cjs, which rewords one comment about
DataStax Enterprise's PENDING keyword. Highlighting is unchanged.

Setting names share their color with JSON and YAML keys, XML attribute
names, and GraphQL argument names. The cyan in use now is only 25 apart
from string values (CIEDE2000), and the indigo before it only 8.9 from
keywords in light mode. Sky is at least 28.8 from keywords and 33.3 from
strings, in both themes.

- Contrast on the code background is 5.68:1 in light mode (sky 700)
  and 6.95:1 in dark mode (sky 400). Every highlighted token in the UI
  preview still passes WCAG AA in both themes.