fix(boards): Elecrow ThinkNode-M2 uses CH340K, not CP2102

The shipping revision of this board has a WCH CH340K USB-UART bridge
(1a86:7522), not a Silicon Labs CP2102 as the original board-module
comment claimed. Update the doc header, and add the CH340K +
CH340-standard VID:PIDs to the `just flash` port list so we stop
falling through to espflash auto-detect on these boards.

justfile

@@ -77,7 +77,7 @@ flash board:
     @read -r feat target chip <<< "$(just _info {{board}})"; \
     case "$target" in \
         xtensa-*) \
-            port=$(just _find_port "303a:1001" "1209:5741" "10c4:ea60"); \
+            port=$(just _find_port "303a:1001" "1209:5741" "10c4:ea60" "1a86:7522" "1a86:7523"); \
             if [ -n "$port" ]; then \
                 echo "Using $port"; \
                 espflash flash -p "$port" "{{builds_dir}}/donglora-{{board}}-v{{version}}.elf"; \