fix: add gatsby back to dev deps

gatsby was accidentally removed from dev deps

Author: sbardian

package.json

@@ -70,6 +70,7 @@
     "eslint-plugin-prettier": "3.3.1",
     "eslint-plugin-react": "7.22.0",
     "eslint-plugin-react-hooks": "4.2.0",
+    "gatsby": "3.0.4",
     "husky": "4.3.8",
     "jest": "26.6.3",
     "jest-dom": "4.0.0",

yarn.lock

@@ -7995,7 +7995,7 @@ gatsby-telemetry@^2.0.0:
     node-fetch "^2.6.1"
     uuid "3.4.0"
 
-gatsby@^3.0.4:
+gatsby@3.0.4:
   version "3.0.4"
   resolved "https://registry.yarnpkg.com/gatsby/-/gatsby-3.0.4.tgz#dce3e44cb85ee6a4cdc71a5be9b3485206bea0fc"
   integrity sha512-LIBeox/O4XlgfpPYScS5LwFreWlZuuz4OZl0cnkA3M8EfxelHwLpqMvOeSYsoMHvogBJzlLocfRQIgzqvXS7kA==