Update commands list and improve command descriptions (#787)

Author: vim-zz

docs/user-commands.md

@@ -22,7 +22,9 @@ and :thumbsup: is added when the command has been successfully executed.
 <div class="commands-details" markdown=1>
 | Command | Platform | Description | Action |
 |---------|----------|-------------|--------|
-| `/gs review` | :fontawesome-brands-github: | Runs a one-time code review on the current PR | Executes `code-review@v1` once on the current PR |
-| `/gs desc` | :fontawesome-brands-github: | Generates or updates the PR description with AI-powered change summary | Executes `describe-changes@v1` once on the current PR with `concat_mode: append` |
-| `/gs help` | :fontawesome-brands-github: | Displays available commands and their descriptions | Adds a new PR comment with the list of available commands |
+| `/gs review` | :fontawesome-brands-github: | Run an AI-powered code review on this PR | Executes `code-review@v1` once on the current PR |
+| `/gs desc` | :fontawesome-brands-github: | Generate a description of the changes in this PR | Executes `describe-changes@v1` once on the current PR with `concat_mode: append` |
+| `/gs etr` | :fontawesome-brands-github: | Add estimated time to review label | Adds a label with the estimated review time based on the PR changes |
+| `/gs code-experts` | :fontawesome-brands-github: | Add a comment with codeExperts suggestion for current changes | Executes `explain_code_experts@v1` once on the current PR |
+| `/gs help` | :fontawesome-brands-github: | Show help message with available commands | Displays a comment with the list of all available gitStream commands |
 </div>