Update docs for newly added commands

[bartekpacia]

We've recently merged many PRs. The ones that need documentation update: (in order from newest to oldest):

• Add optional field to commands Maestro#1946 -> Add docs for optional #91
• Add configuration file parameter to test, cloud and record commands Maestro#1829
• Add --shard-all and --shard-split options to test command Maestro#1955 -> Update docs to mention running tests in parallel (--shard-all and --shard-split) #90
• Add back CLI --platform option Maestro#1954
• Add filename to env Maestro#1945
• Fix android open link verify Maestro#1999
• Add --generate-completion command Maestro#2002
• Add --verbose flag that prints all logs to stdout Maestro#1987
• Delete apks after using them Maestro#1947
• Allow env variables in setLocation and travel commands Maestro#1988

[Fishbowler]

Needed:

• Verbose should get docs, but unsure where
• MAESTRO_FILENAME env var needs to go somewhere, but it's generated not provided by the user
• Use of --config definitely needs to go in

Unsure:

• Unclear how to generate completion

> maestro --generate-completion
Unknown option: '--generate-completion'

Not needed (so ticked off):

• --platform never got removed from the docs, so no need to add
• Deleting APKs was a bug fix
• Allowing vars in location-related commands was a bug fix