add theme testbench command

crates/zed/Cargo.toml

@@ -50,6 +50,7 @@ text = { path = "../text" }
 terminal = { path = "../terminal" }
 theme = { path = "../theme" }
 theme_selector = { path = "../theme_selector" }
+theme_testbench = { path = "../theme_testbench" }
 util = { path = "../util" }
 vim = { path = "../vim" }
 workspace = { path = "../workspace" }

crates/zed/src/main.rs

@@ -119,6 +119,7 @@ fn main() {
         search::init(cx);
         vim::init(cx);
         terminal::init(cx);
+        theme_testbench::init(cx);
 
         let db = cx.background().block(db);
         cx.spawn(|cx| watch_themes(fs.clone(), themes.clone(), cx))