docs: update docs for named source commands

Author: nick4eva

docs/reference/03-channel-spec.md

@@ -56,6 +56,7 @@ Defines what data the channel searches through.
 | Field | Type | Required | Description |
 |-------|------|----------|-------------|
 | `command` | string or string[] | Yes | Command(s) that produce entries |
+| `command_name` | string or string[] | No | Display name(s) for source commands, shown in the results panel header when cycling |
 | `ansi` | boolean | No | Parse ANSI escape codes (default: false) |
 | `display` | string | No | Template for display (incompatible with `ansi = true`) |
 | `output` | string | No | Template for final output |
@@ -79,6 +80,18 @@ command = ["fd -t f", "fd -t f -H", "fd -t f -H -I"]
 # Press Ctrl+S to cycle between commands
 ```
 
+### Named Source Commands
+
+When using multiple source commands, you can give each one a display name.
+The name replaces the generic "Results" label in the results panel header,
+making it easy to see which source is active.
+
+```toml
+[source]
+command = ["fd -t f", "fd -t f -H", "fd -t f -H -I"]
+command_name = ["Default", "Hidden", "All"]
+```
+
 ### With ANSI Colors
 
 ```toml
@@ -354,6 +367,7 @@ requirements = ["docker"]
 [source]
 command = ["docker ps --format '{{.ID}}\\t{{.Names}}\\t{{.Status}}'",
            "docker ps -a --format '{{.ID}}\\t{{.Names}}\\t{{.Status}}'"]
+command_name = ["Running", "All"]
 display = "{split:\\t:1} | {split:\\t:2}"
 output = "{split:\\t:0}"