docs(iroh-cli): update tags command documentation (#2709)

## Description

<!-- A summary of what this pull request achieves and a rough list of
changes. -->
Update documentation to `tags` command.

This partially addresses #2660, and belongs to a series of PRs to
complete it

## Breaking Changes

<!-- Optional, if there are any breaking changes document them,
including how to migrate older code. -->

## Notes & open questions

Imports have been formated to be grouped.

## Change checklist

- [ ] Self-review.
- [X] Documentation updates following the [style
guide](https://rust-lang.github.io/rfcs/1574-more-api-documentation-conventions.html#appendix-a-full-conventions-text),
if relevant.
- [ ] Tests if relevant.
- [ ] All breaking changes documented.

iroh-cli/src/commands/tags.rs

@@ -1,10 +1,12 @@
+//! Define the tags subcommand.
+
 use anyhow::Result;
 use bytes::Bytes;
 use clap::Subcommand;
 use futures_lite::StreamExt;
-use iroh::blobs::Tag;
-use iroh::client::Iroh;
+use iroh::{blobs::Tag, client::Iroh};
 
+/// Commands to manage tags.
 #[derive(Subcommand, Debug, Clone)]
 #[allow(clippy::large_enum_variant)]
 pub enum TagCommands {
@@ -19,6 +21,7 @@ pub enum TagCommands {
 }
 
 impl TagCommands {
+    /// Runs the tag command given the iroh client.
     pub async fn run(self, iroh: &Iroh) -> Result<()> {
         match self {
             Self::List => {