Use the --tools flag multiple times

We use StringArrayVar which doesn't split on comma.

Author: eleftherias

docs/toolhive/guides-cli/run-mcp-servers.mdx

@@ -153,7 +153,7 @@ same MCP server, but it is not meant as a security feature.
 To filter the list of tools, use the `--tools` flag either once
 
 ```bash
-thv run --tools <TOOL_1>,<TOOL_2> <SERVER>
+thv run --tools <TOOL_1> <SERVER>
 ```
 
 Or multiple times
@@ -165,7 +165,7 @@ thv run --tools <TOOL_1> --tools <TOOL_2> <SERVER>
 For example:
 
 ```bash
-thv run --tools list_issues,get_issue github
+thv run --tools list_issues --tools get_issue github
 ```
 
 If the server comes from the registry, ToolHive can validate the tool names