* Display aliases and custom commands in which; Fix#2810
Example output of nu after the commit is applied:
```shell
/home/leo/repos/nushell(feature/which_inspect_alias)> def docker-ps [] { docker ps --format '{{json .}}' | from json -o }
/home/leo/repos/nushell(feature/which_inspect_alias)> which docker-ps
───┬───────────┬────────────────────────┬─────────
# │ arg │ path │ builtin
───┼───────────┼────────────────────────┼─────────
0 │ docker-ps │ nushell custom command │ No
───┴───────────┴────────────────────────┴─────────
/home/leo/repos/nushell(feature/which_inspect_alias)> alias d = gid pd
/home/leo/repos/nushell(feature/which_inspect_alias)> which d
───┬─────┬───────────────┬─────────
# │ arg │ path │ builtin
───┼─────┼───────────────┼─────────
0 │ d │ nushell alias │ No
───┴─────┴───────────────┴─────────
```
* Update documentation
* Begin allowing comments and multiline scripts.
* clippy
* Finish moving to groups. Test pass
* Keep going
* WIP
* WIP
* BROKEN WIP
* WIP
* WIP
* Fix more tests
* WIP: alias starts working
* Broken WIP
* Broken WIP
* Variables begin to work
* captures start working
* A little better but needs fixed scope
* Shorthand env setting
* Update main merge
* Broken WIP
* WIP
* custom command parsing
* Custom commands start working
* Fix coloring and parsing of block
* Almost there
* Add some tests
* Add more param types
* Bump version
* Fix benchmark
* Fix stuff
* added math round
* added math floor
* added math ceil
* added math.md examples
* moved the detection of nonnumerical values in ceil/floor/round
* math round now works on streams
* math floor now works on streams
* math ceil now works on streams
* First draft for adding a `pretty` flag to `to md`
* rustfmt
* Fix Clippy warnings
* rustfmt
* Using Clippy suggestion broken code, reverting and putting in a statement to ignore clippy warning
* Add test for `to md -p`
* Add deserialization of Primitive::Duration; Fixes#2373
* Implement Sleep command
* Add comment saying you should name your rest field "rest"
* Fix typo
* Add documentation for sleep command
* Rename `calc` to `math eval` and allow it to optionally take the expression as an argument
* Moved calc tests to math eval
Also added 2 tests and changed 1 test
* Move calc docs to math eval
* Very rough idea
* Remove colour codes
* Work on command for generating docs
* Quick comment
* Use nested collapsible markdown
* Refine documentation command
* Clippy and rename docs
* This layout probably seems best
Also moved some code to documentation.rs to avoid making help.rs massive
* Delete summaries.md
* Add usage strings
* Remove static annotations
* get_documentation produces value
Which will be used like
'help generate_docs | save "something"'
The resulting yaml can be passed to a script for generating HTML/MD files in the website
* Fix subcommands
* DRY code
* Address clippy:
* Fix links
* Clippy lints
* Move documentation to more central location
