Specifically, functions that are run in the context of the test runner
are put in module `test/testutil.lua` while the functions that are run
in the context of the test session are put in
`test/functional/testnvim.lua`.
Closes https://github.com/neovim/neovim/issues/27004.
- Added `@inlinedoc` so single use Lua types can be inlined into the
functions docs. E.g.
```lua
--- @class myopts
--- @inlinedoc
---
--- Documentation for some field
--- @field somefield integer
--- @param opts myOpts
function foo(opts)
end
```
Will be rendered as
```
foo(opts)
Parameters:
- {opts} (table) Object with the fields:
- somefield (integer) Documentation
for some field
```
- Marked many classes with with `@nodoc` or `(private)`.
We can eventually introduce these when we want to.
