* tests: adds tests for default values triggering conditional requirements
* fix: fixes a bug where default values should have triggered a conditional requirement but didnt
Closes#831
* tests: adds tests for missing conditional requirements in usage string of errors
* fix: fixes a bug where conditionally required args werent appearing in errors
* tests: adds tests for completion generators
* tests: adds tests for completions with binaries names that have underscores
* fix: fixes a bug where ZSH completions would panic if the binary name had an underscore in it
Closes#581
* fix: fixes bash completions for commands that have an underscore in the name
Closes#581
* chore: fix the category for crates.io
* docs(Macros): adds a warning about changing values in Cargo.toml not triggering a rebuild automatically
Closes#838
* fix(Completions): fixes a bug where global args weren't included in the generated completion scripts
Closes#841
* fix: fixes a println->debugln typo
* chore: increase version
* fix: fixes a critical bug where subcommand settings were being propogated too far
Closes#832
* imp: adds ArgGroup::multiple to the supported YAML fields for building ArgGroups from YAML
Closes#840
* chore: increase version
* Clap has dependencies even with all features disabled.
* The "nightly" feature does nothing, so don't mention it.
* Explain the difference between "unstable" and "nightly" better.
* Split features into groups (default, opt-in, clap-development).
* For contributors: update what tests should be run, and remove make command.
* Removes a repeated word and splits up some long markdown lines.
Also groups features by category and dependencies by feature in Cargo.toml.
