fix: some docs issues with reviewer

Co-authored-by: ZHANG Yuntian <[email protected]>

docs/cmd/rsdk-shell.md

@@ -1,4 +1,5 @@
 # `rsdk-shell`
 
-Please run `rsdk shell` before performing any operations.  
-This will automate the development environment configuration.
+It is recommended to run `rsdk shell` first to set up the work environment before running other commands.  
+However, most commands should run without issue.  
+Some enhancements (for example, bash completion and shell prompt) may not be available outside of `rsdk shell` by default.

docs/tutorials/usage.md

@@ -14,14 +14,11 @@ Running a command with `--help` argument will display its help text.
 
 When it is run without any argument, `rsdk-tui` will be run instead.
 
-1. Enter TUI
+1. Start TUI Wizard by running `rsdk` in the terminal.
 
-```bash
-rsdk
-```
-
-2. Select the task you want to use. You can use arrow key to navigate, use Enter key to select, and use Escape key to leave current window.
-   In this example we will choose `Build system image`:
+2. Select the task you want to run.
+   You can use arrow key to navigate, use Enter key to select, and use Escape key to leave current window.
+   In this example, we will choose `Build system image`:
 
 ```bash
 ┌─────────────────┤ RSDK ├──────────────────┐
@@ -36,8 +33,9 @@ rsdk
 └───────────────────────────────────────────┘
 ```
 
-3. Select which product you want to build. You can use the space bar to select the product, and the chosen product will have asterisk symbol placed in the parentheses. **Enter key does not select the product when used alone!**
-   In this example we will choose `rock-5b-6_1`:
+3. Select the product you want to build.
+   You can use the space bar to select the product, and the chosen product will have asterisk symbol placed in the parentheses. **Enter key does not select the product when used alone!**
+   In this example, we will choose `rock-5b-6_1`:
 
 ```bash
 ┌─────────────────┤ RSDK ├──────────────────┐
@@ -52,7 +50,8 @@ rsdk
 └───────────────────────────────────────────┘
 ```
 
-4. Select `Yes` to start the build process. `rsdk-tui` will then run the associated CLI commands to complete the task:
+4. Select `Yes` to start the build process.
+   `rsdk-tui` will then run the associated CLI commands to complete the task:
 
 ```bash
 ┌─────────────────┤ RSDK ├──────────────────┐

src/libexec/rsdk/rsdk-help

@@ -37,7 +37,7 @@ rsdk-${FUNCNAME[0]##rsdk-help-}
         serve both Radxa archives as well as any other 3rd party archives.
 
         The following archives will use this mirror:
-    $(find "$SCRIPT_DIR/../../../externals/keyrings/" -maxdepth 1 -mindepth 1 -type d ! -name debian -a ! -name ubuntu -printf "        %f\n")
+$(find "$SCRIPT_DIR/../../../externals/keyrings/" -maxdepth 1 -mindepth 1 -type d ! -name debian -a ! -name ubuntu -printf "            %f\n")
     -i | --image-name [image_name]
         Set the system image name. (Default: $("$SCRIPT_DIR/../../bin/rsdk" config build.default_image_name))
     -h | --help