docs(glossary): Add short history about the hash routing

[dipikabh]

Description

This PR primarily adds the "Brief history of hash-based SPA routing" section to the Router glossary page.

Other changes are minor edits for formatting, punctuation, and clarity on the "Router" and Working with the History API pages.

Motivation

We were missing historical context for hash routing. The new section informs developers why #/ and #!/ routing practices came about, why they are obsolete now, and what to use instead.

/cc @tantek

[github-actions]

Preview URLs

• /en-US/docs/Glossary/Router
• /en-US/docs/Web/API/History_API/Working_with_the_History_API

External URLs (4)

URL: /en-US/docs/Glossary/Router
Title: Router

• https://angular.dev/guide/routing/common-router-tasks (1 time) (Note! This may be a new URL 👀)
• https://en.wikipedia.org/wiki/Router_(computing) (1 time) (Note! This may be a new URL 👀)
• https://reactrouter.com/ (1 time) (Note! This may be a new URL 👀)
• https://router.vuejs.org/ (1 time) (Note! This may be a new URL 👀)

[Josh-Cena]

What about a separate entry called "hash routing"?

[bsmth]

What about a separate entry called "hash routing"?

I think this is a good idea, what do you think, Dipika?