Unnecessary notations in doc comments

[lapla-cogito]

There are some unnecessary notations in clippy_lints like this:

rust-clippy/clippy_lints/src/strings.rs

Line 373 in c4aeb32

/// // example code where clippy issues a warning

This would come from clippy_dev/src/new_lint.rs:

rust-clippy/clippy_dev/src/new_lint.rs

Line 333 in c4aeb32

/// // example code where clippy issues a warning

Since lines like this are treated as document comment, these sentences are included in the Web page:

While most other items exclude this:

So I believe these unnecessary notations should be removed.