Init: init first version of pcode-cli

Change log:
* Added the ability to display a list of all templates.
* Added the ability to download a template.
* Defined the project structure.

src/lib.rs

@@ -0,0 +1,67 @@
+mod cli;
+mod config;
+mod core;
+mod misc;
+mod templates;
+
+use std::process;
+
+use clap::Parser;
+use cli::{CLI, Commands, TemplateAction};
+use config::{Config, load_config};
+use templates::{list_templates, load_template};
+
+fn parse_config() -> Config {
+    let cfg: Config = match load_config() {
+        Ok(cfg) => cfg,
+        Err(err) => {
+            eprintln!("{}", err);
+            process::exit(1);
+        }
+    };
+
+    cfg
+}
+
+fn process_command(cfg: Config) {
+    let cli = CLI::parse();
+
+    match cli.command {
+        Some(Commands::Template(template_command)) => match template_command.action {
+            TemplateAction::List => {
+                let templates = match list_templates(&cfg.templates_dir) {
+                    Ok(temps) => temps,
+                    Err(err) => {
+                        eprintln!("{}", err);
+                        process::exit(1);
+                    }
+                };
+
+                // TODO: Add grouping by language.
+                for template in templates {
+                    eprintln!("{} >- {}", template.language, template.name);
+                }
+            }
+            TemplateAction::Load { name, vars } => match load_template(&cfg.templates_dir, &name) {
+                Ok(_) => {
+                    eprintln!("Template succesfully copied!");
+                    eprintln!("Vars: {:?}", vars);
+                }
+                Err(err) => {
+                    eprintln!("{}", err);
+                    process::exit(1)
+                }
+            },
+        },
+        None => {
+            eprintln!("No command provided. Use --help for usage.");
+            process::exit(1);
+        }
+    }
+}
+
+pub fn run() {
+    let cfg = parse_config();
+
+    process_command(cfg);
+}