doc: remove ineffective inline code blocks

[brackendawson]

Summary

Godoc does not have inline code blocks. Look to the standard library for conventions for inline references to code.

Changes

• Replace inline code blocks in docs (uses backticks) with formats following the conventions of the standard library.

Motivation

Go doc does not have inline code blocks and backticks are unusual quotes for human readable documentation.

Related issues

Closes #1713

[brackendawson]

I discovered #1712 while making this change. I also noticed that suite.Suite.Assert() probably isn't necessary, you can just do:

func (s *MySuite) TestIfy() {
    s.Assertsions.True(true)
}

You can't travel far in testify without tripping over strange functions.

[dolmen]

@brackendawson I would prefer that we split commits based on the {assert,require}/mock/suite package groups. Because it gives more relevant Git history. Of course this is a general rule that deserves exceptions.

In this case, the change in suite are a (good) reword of some doc, not the quotes change like elsewhere, so that would deserves being its own commit, or even its own PR.