Add Prepare step

package.json

@@ -50,6 +50,7 @@
     "data": "rsync -r node_modules/vega-datasets/data/* site/data",
     "format": "eslint . --fix && yarn prettierbase --write",
     "lint": "eslint . && yarn prettierbase --check",
+    "prepare": "yarn build",
     "prebuild": "yarn clean:build",
     "prebuild:examples": "yarn build:only",
     "prebuild:examples-full": "yarn build:only",

yarn.lock

@@ -7587,6 +7587,14 @@ vega-expression@^5.0.1, vega-expression@^5.1.1, vega-expression@~5.1.1:
     "@types/estree" "^1.0.0"
     vega-util "^1.17.2"
 
+vega-expression@~5.1.2:
+  version "5.1.2"
+  resolved "https://registry.yarnpkg.com/vega-expression/-/vega-expression-5.1.2.tgz#1ed0677787b8e5f4047c9b847ecc20da0a2a8d05"
+  integrity sha512-fFeDTh4UtOxlZWL54jf1ZqJHinyerWq/ROiqrQxqLkNJRJ86RmxYTgXwt65UoZ/l4VUv9eAd2qoJeDEf610Umw==
+  dependencies:
+    "@types/estree" "^1.0.0"
+    vega-util "^1.17.3"
+
 vega-force@~4.2.1:
   version "4.2.1"
   resolved "https://registry.yarnpkg.com/vega-force/-/vega-force-4.2.1.tgz#bdce6ec8572867b4ff2fb7e09d2894798c5358ec"
@@ -7814,6 +7822,11 @@ vega-util@^1.17.1, vega-util@^1.17.2, vega-util@~1.17.2:
   resolved "https://registry.yarnpkg.com/vega-util/-/vega-util-1.17.2.tgz#f69aa09fd5d6110c19c4a0f0af9e35945b99987d"
   integrity sha512-omNmGiZBdjm/jnHjZlywyYqafscDdHaELHx1q96n5UOz/FlO9JO99P4B3jZg391EFG8dqhWjQilSf2JH6F1mIw==
 
+vega-util@^1.17.3, vega-util@~1.17.3:
+  version "1.17.3"
+  resolved "https://registry.yarnpkg.com/vega-util/-/vega-util-1.17.3.tgz#8f24d867daae69580874dcf75de10c65ac9ede5d"
+  integrity sha512-nSNpZLUrRvFo46M5OK4O6x6f08WD1yOcEzHNlqivF+sDLSsVpstaF6fdJYwrbf/debFi2L9Tkp4gZQtssup9iQ==
+
 vega-view-transforms@~4.6.0:
   version "4.6.0"
   resolved "https://registry.yarnpkg.com/vega-view-transforms/-/vega-view-transforms-4.6.0.tgz#829d56ca3c8116b0dded4ec0502f4ac70253de9a"