Migrate to docs.substrate.io throughout (#10007)

* all reverences of substrate.dev replaced with *correct* docs.substrate.io links

* fix links in non-cargo files, errors in replace

* homepage https://substrate.io

* cargo +nightly fmt

* FMT

Co-authored-by: Bastian Köcher <info@kchr.de>

substrate/frame/contracts/README.md

@@ -34,7 +34,7 @@ reverted at the current call's contract level. For example, if contract A calls
 then all of B's calls are reverted. Assuming correct error handling by contract A, A's other calls and state
 changes still persist.
 
-One gas is equivalent to one [weight](https://substrate.dev/docs/en/knowledgebase/learn-substrate/weight)
+One gas is equivalent to one [weight](https://docs.substrate.io/v3/runtime/weights-and-fees)
 which is defined as one picosecond of execution time on the runtime's reference machine.
 
 ### Notable Scenarios