Pattern based verb arguments

Here are some examples of verbs which can be configured now.

	[[verbs]]
	invocation = "mkdir {subpath}"
	execution = "/bin/mkdir -p {directory}/{subpath}"

As before, when only one verb possibly matches, you don't have to type its
complete name. You can do

	mk new folder

(and yes, space are ok)

	[[verbs]]
	invocation = "create {subpath}"
	execution = "/usr/bin/nvim {directory}/{subpath}"

	[[verbs]]
	invocation = "rm"
	execution = "/bin/rm -rf {file}"
	confirm = true
	leave_broot = false

	[[verbs]]
	invocation = "mv {subpath}"
	execution = "/bin/mv {file} {parent}/{subpath}"

Here's a more complex one, creating a directory then a file in neovim, by
destructuring the argument in name and suffix:

	[[verbs]]
	invocation = "blop {name}\\.{type}"
	execution = "/bin/mkdir {parent}/{type} && /usr/bin/nvim {parent}/{type}/{name}.{type}"
	from_shell = true

Notice the `\\.` ? That's because the invocation pattern is interpreted as a regular expression
(with just a shortcut for the easy case, enablinrg `{name}`).
The whole regular expression syntax may be useful for more complex rules.
Let's say we don't want the type to contain dots, then we do this:

	[[verbs]]
	invocation = "blop {name}\\.(?P<type>[^.]+)"
	execution = "/bin/mkdir {parent}/{type} && /usr/bin/nvim {parent}/{type}/{name}.{type}"
	from_shell = true

1 files changed, 3 insertions, 1 deletions

diff --git a/src/main.rs b/src/main.rs
index 7cb2cdc..08d6ccb 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -38,6 +38,8 @@ mod tree_build;
 mod tree_options;
 mod tree_views;
 mod verbs;
+mod verb_invocation;
+mod verb_store;
 
 use log::LevelFilter;
 use simplelog;
@@ -51,7 +53,7 @@ use crate::app_context::AppContext;
 use crate::conf::Conf;
 use crate::errors::ProgramError;
 use crate::external::Launchable;
-use crate::verbs::VerbStore;
+use crate::verb_store::VerbStore;
 
 // There's no log unless the BROOT_LOG environment variable is set to
 //  a valid log level (trace, debug, info, warn, error, off)