vscode: Add task to watch build errors

.vscode/tasks.json

@@ -0,0 +1,17 @@
+{
+    "version": "2.0.0",
+    "tasks": [
+      {
+        "type": "npm",
+        "script": "errors",
+        "problemMatcher": "$tsc-watch",
+        "isBackground": true,
+        "presentation": {
+          "revealProblems": "never"
+        },
+        "runOptions": {
+          "runOn": "folderOpen"
+        }
+      }
+    ]
+  }

package.json

@@ -31,7 +31,8 @@
     "test-jasmine": "TRILIUM_DATA_DIR=./data-test ts-node ./node_modules/.bin/jasmine",
     "test-es6": "ts-node -r esm spec-es6/attribute_parser.spec.ts",
     "test": "npm run test-jasmine && npm run test-es6",
-    "postinstall": "rimraf ./node_modules/canvas"
+    "postinstall": "rimraf ./node_modules/canvas",
+    "errors": "tsc --watch --noEmit"
   },
   "dependencies": {
     "@braintree/sanitize-url": "6.0.4",