Wiki Reorg: Bridges (#6192)

* added comparison table

* moved content

- rm bridge hub page
- move to sys chain page
- redirects and sidebar edits

* redirect polkadot

* reorg text

rm outdated content

* moved table

* minor edit

* edits comparison

text snowbridge and bridges

* added notes and links

* edits BEEFY

* added text

* minor edits text

* Bhargav feedback

* minor edit

* Update docs/learn/learn-snowbridge.md

Co-authored-by: bader y <ibnbassem@gmail.com>

* Bader's feedback

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Co-authored-by: bader y <ibnbassem@gmail.com>

docs/general/glossary.md

@@ -691,7 +691,7 @@ parachains. For developers, see the
 
 Parachains that are part of the Polkadot core protocol. These are allocated a parachain execution
 core by governance rather than by auction. Examples of system parachains include
-[Asset Hub](../learn/learn-assets.md), [Bridge Hub](../learn/learn-bridge-hub.md),
+[Asset Hub](../learn/learn-assets.md), [Bridge Hub](../learn/learn-system-chains.md#bridge-hub),
 [Collectives](../learn/learn-system-chains.md#collectives) and People Chain.
 
 ## Tabling