Auto merge of #63045 - Rosto75:master, r=jonas-schievink
Auto merge of #63045 - Rosto75:master, r=jonas-schievink

Change the placement of two functions.

Right now, the order is as follows:
`pop_front()`
`push_front()`
`push_back()`
`pop_back()`

`swap_remove_back()`
`swap_remove_front()`

I believe it would be more natural, and easier to follow, if we place `pop_back()` right after the `pop_front()`, and `swap_remove_back()` after the `swap_remove_front()` like this:
`pop_front()`
`pop_back()`
`push_front()`
`push_back()`

`swap_remove_front()`
`swap_remove_back()`

The rest of the documentation (at least in this module) adheres to the same logic, where the 'front' function always precedes its 'back' equivalent.

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