Rollup merge of #87865 - tsoutsman:master, r=GuillaumeGomez
Rollup merge of #87865 - tsoutsman:master, r=GuillaumeGomez

Clarify terms in rustdoc book

Fixes #70898

I chose to completely remove the term directive over attribute because rustdoc has a lint called `invalid_codeblock_attributes` and the term attributes is used throughout the book. I slightly changed the introductory sentence to describe the relationship between annotations and attributes.

I also moved the text explaining the example from below the blocks to above the blocks which is more in line with the rest of the book. I also changed the description for the `should_panic` attribute as I found it a little confusing. Finally, some of the blocks were `text` and some were `rust` so I changed them all to `text` which is in line with the rest of the book.

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