feat: add compose exec and compose bash commands

Exec is new command scoped under compose. It allows sending commands
directly into appserver container. I will make this
customizable/controllable in the future.

src/cli/django.rs

@@ -31,7 +31,7 @@ pub enum Django {
 
     /// Run Django's manage.py shell.
     Shell,
-    
+
     /// Run Django's manage.py test.
     Test,
 }

src/cli/docker_compose.rs

@@ -5,12 +5,21 @@ use clap::Subcommand;
 /// Wraper for docker compose; autodiscover compose file and source .env file.
 #[derive(Subcommand, Debug)]
 pub enum DockerCompose {
+    /// Start bash session inside container
+    Bash,
+
     /// Build containers.
     Build,
 
     /// Down containers.
     Down,
 
+    /// Exec command inside container.
+    Exec {
+        #[arg(value_enum)]
+        rest: Vec<String>,
+    },
+
     /// Stop, build and start containers.
     Rebuild,