Rollup merge of #28743 - JanLikar:master, r=steveklabnik
Rollup merge of #28743 - JanLikar:master, r=steveklabnik

 - Expand the first paragraph

 - Improve readability by partitioning the chapter into the following
   sections: "Patterns", "Type annotations", "Mutability", and
   "Initializing bindings"

 - Add "Scope and shadowing" section (fix #28177)

r? @steveklabnik

graydon/rust,aidancully/rust,graydon/rust,aidancully/rust,graydon/rust,GBGamer/rust,graydon/rust,GBGamer/rust,aidancully/rust,aidancully/rust,GBGamer/rust,graydon/rust,aidancully/rust,GBGamer/rust,GBGamer/rust,GBGamer/rust,graydon/rust,GBGamer/rust,GBGamer/rust,aidancully/rust