Add jpm repl subcommand and post-deps macro for jpm.

This will allow more flexibility in writing jpm project files.

jpm.1

@@ -24,6 +24,10 @@ More interesting are the local commands. For more information on jpm usage, see
 
 .SH FLAGS
 
+.TP
+.BR \-\-nocolor
+Disable color in the jpm repl.
+
 .TP
 .BR \-\-verbose
 Print detailed messages of what jpm is doing, including compilation commands and other shell commands.
@@ -154,6 +158,11 @@ The main function is the entry point of the program and will receive command lin
 as function arguments. The entry file can import other modules, including native C modules, and
 jpm will attempt to include the dependencies into the generated executable.
 
+.TP
+.BR repl
+Load the current project.janet file and start a repl in it's environment. This lets a user better
+debug the project file, as well as run rules manually.
+
 .SH ENVIRONMENT
 
 .B JANET_PATH