Drop yarn in favor of npm

.devcontainer/devcontainer.json

@@ -15,14 +15,14 @@
     "dbaeumer.vscode-eslint",
     "esbenp.prettier-vscode",
     "bierner.lit-html",
-    "runem.lit-plugin",
+    "runem.lit-plugin"
   ],
 
   // Use 'forwardPorts' to make a list of ports inside the container available locally.
-	// "forwardPorts": [],
+  "forwardPorts": [5000],
 
   // Use 'postCreateCommand' to run commands after the container is created.
-	// "postCreateCommand": "yarn install",
+  "postCreateCommand": "npm install",
 
   // Comment out connect as root instead. More info: https://aka.ms/vscode-remote/containers/non-root.
   "remoteUser": "node",
@@ -41,5 +41,4 @@
     },
     "files.trimTrailingWhitespace": true
   }
-
 }

.gitignore

@@ -1,3 +1,2 @@
 dist
 node_modules
-yarn-error.log

script/build

@@ -4,5 +4,5 @@ set -e
 cd "$(dirname "$0")/.."
 
 rm -rf dist
-NODE_ENV=production yarn tsc
+NODE_ENV=production npm exec -- tsc
-NODE_ENV=production yarn rollup -c
+NODE_ENV=production npm exec -- rollup -c

script/develop

@@ -11,7 +11,7 @@ trap "kill 0" EXIT
 # Run tsc once as rollup expects those files
 tsc || true
 
-yarn serve &
+npm exec -- serve &
-yarn tsc --watch &
+npm exec -- tsc --watch &
-yarn rollup -c --watch &
+npm exec -- rollup -c --watch &
 wait