Remove the AddPost command.

I will be putting this back in later but having the skeleton sitting there unused has no value at this time.

src/command/build/mod.rs

@@ -0,0 +1,3 @@
+mod runner;
+
+pub(crate) use runner::build_site;

src/command/build/runner.rs

@@ -0,0 +1,7 @@
+use crate::cli::parameters::BuildArgs;
+use crate::config::Config;
+
+pub(crate) async fn build_site(args: BuildArgs) -> Result<(), Box<dyn std::error::Error>> {
+    let _config = Config::load_from_file(args.config).await?;
+    Ok(())
+}