Fixes errors when building docs.

[thejpster]

Fixes:

warning: unresolved link to `OverlapIterator`
  --> src\lib.rs:13:26
   |
13 | /// Currently contains [`OverlapIterator`]
   |                          ^^^^^^^^^^^^^^^ no item named `OverlapIterator` in scope
   |
   = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
   = note: `#[warn(rustdoc::broken_intra_doc_links)]` on by default

warning: unresolved link to `Regions`
  --> src\iter.rs:48:75
   |
48 | /// Blanket implementation for all types implementing [`Iterator`] over [`Regions`]
   |                                                                           ^^^^^^^ no item named `Regions` in scope
   |
   = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`

warning: `embedded-storage` (lib doc) generated 2 warnings