make hooks messages configurable

[zach-sherman]

...and update them to reflect current usage

why:

• these messages appeared to be just wrong (referencing aide instead of firstaide or an update command that doesn't appear to exist)
• and in any case it's nice to have them all customizeable not just the getting_started message. based on the presence of the Messages struct I presume this was always intended

how:

• add fields to Messages struct, named based on the hook they are associated with
• set sensible defaults for messages
• add messages to the hooks scripts
• splat configured messages into hooks scripts based on how it was done for the getting_started message

docs: updated the readme to document messages configuration

validation: tested new message configurations in a different project, cargo test

[zach-sherman]

here's a demo of how the default messages show up now:

$ .cache/firstaide-bin/bin/firstaide build
2023-10-25 10:50:42  INFO  Allow direnv in "/Users/z".
2023-10-25 10:50:42  INFO  Create cache dir at ".cache/firstaide-cache".
2023-10-25 10:50:42  INFO  Capture outside environment.
⠙ 2023-10-25 10:50:43  INFO  Capture inside environment (may involve a full build).
⠸ 2023-10-25 10:50:52  INFO  Calculate environment diff.
2023-10-25 10:50:52  INFO  Calculate file checksums.
⠙ 2023-10-25 10:50:52  INFO  Write out cache.
2023-10-25 10:50:52  INFO  Update most recent cache file link.
direnv: loading .envrc                                                                                                                
direnv: OKAY: Nix environment is up to date!
direnv: This is a minimal environment; subprojects may not be built.
direnv: --> Use firstaide --help to find out what to do next.
direnv:         ^^^^^^^^^^^^^^^^
direnv: export +AR +AS +AWS_PROFILE ...
$ rm -rf .cache/firstaide-cache
direnv: loading .envrc                                                                                                                
direnv: ERROR: Nix environment is not yet built!
direnv: --> Use build firstaide and run "firstaide build" to build it.
direnv:         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
$ firstaide build    
2023-10-25 10:51:09  INFO  Allow direnv in "/Users/z/".
2023-10-25 10:51:09  INFO  Create cache dir at "/Users/z/.cache/firstaide-cache".
2023-10-25 10:51:09  INFO  Capture outside environment.
⠙ 2023-10-25 10:51:09  INFO  Capture inside environment (may involve a full build).
⠹ 2023-10-25 10:51:12  INFO  Calculate environment diff.
2023-10-25 10:51:12  INFO  Calculate file checksums.
⠙ 2023-10-25 10:51:12  INFO  Write out cache.
2023-10-25 10:51:12  INFO  Update most recent cache file link.
direnv: loading .envrc                                                                                                                
direnv: OKAY: Nix environment is up to date!
direnv: This is a minimal environment; subprojects may not be built.
direnv: --> Use firstaide --help to find out what to do next.
direnv:         ^^^^^^^^^^^^^^^^
direnv: export +AR +AS +AWS_PROFILE ...
# edit flake.nix and:
$  direnv reload                   
direnv: loading .envrc                                                                                                                
direnv: WARNING: Nix environment is out of date! 
direnv: --> Use firstaide build to rebuild it.
direnv:         ^^^^^^^^^^^^^^^
direnv: WARNING: Loading STALE environment ;-(

[zach-sherman]

aaand now it allows you to mix default + custom messages. let me know if there's anything else you'd like to see!