docs: normalize product name casing across docs

[erkamyaman]

Several user-facing docs, tooltips, and tutorial code samples used non-canonical spellings of product names. This normalizes them to the form each project uses for its own brand.

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://github.com/angular/angular/blob/main/CONTRIBUTING.md#commit
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Documentation content changes
• Other... Please describe:

What is the current behavior?

Several user-facing docs, tooltips, and tutorial code samples use
non-canonical spellings of product names:

What is the current behavior?

Several user-facing docs, tooltips, and tutorial code samples use
non-canonical spellings of product names:

• github (lowercase) in a footer tooltip → should be GitHub
• Typescript in prose → should be TypeScript
• NodeJS in a tutorial doc and in an update-guide step label →
  should be Node.js
• StackOverflow in a saved issue reply and a package README →
  should be Stack Overflow
• MacOS in prose and in a @for tutorial code sample (which
  renders to the DOM) → should be macOS
• NPM in prose, including a section heading and an update-guide
  step label → should be npm
• JQuery in prose (TS type names from @types/jquery left
  untouched) → should be jQuery
• [less] and [stylus] link text in the CSS preprocessor list →
  should be [Less] and [Stylus]
• Http Title-Cased in a section heading, table cell, and link
  text even though HTTP is an uppercase acronym and the rest of
  the docs consistently say "HTTP client" / "HTTP interceptor"
• GitHub pages (lowercase 'p') in the deployment table → should
  be GitHub Pages
• Stackblitz in prose across the kitchen-sink page and an
  example readme → should be StackBlitz
• Webcontainer in two testing docs → should be WebContainer

What is the new behavior?

Each reference uses the canonical spelling each project publishes for itself:

• GitHub / GitHub Pages
• TypeScript
• Node.js
• Stack Overflow → logo renders as two words
• macOS → lowercase 'm'
• npm → registry brands itself lowercase
• jQuery → lowercase 'j' (prose only; the JQuery TypeScript type from @types/jquery is left untouched)
• Less / Stylus
• StackBlitz
• WebContainer
• HTTP → uppercase acronym; matches existing "HTTP client" / "HTTP interceptor" usage in adev/src/content/guide/http/overview.md

Does this PR introduce a breaking change?

• Yes
• No