fix: remove gatsby peer dependencies (#182)

Author: Rodrigo54

package.json

@@ -70,9 +70,6 @@
     "vscode-oniguruma": "^1.4.0",
     "vscode-textmate": "^5.2.0"
   },
-  "peerDependencies": {
-    "gatsby": "^2.12.1 || ^3.1.1"
-  },
   "jest": {
     "testMatch": [
       "<rootDir>/test/index.js"