Add eslint and prettier

.eslintrc

@@ -0,0 +1,19 @@
+{
+  "extends": [
+    "react-app",
+    "airbnb",
+    "plugin:jsx-a11y/recommended",
+    "prettier"
+  ],
+  "plugins": [
+    "jsx-a11y",
+    "prettier"
+  ],
+  "rules": {
+    "prettier/prettier": [
+      "error", {
+        "semi": false
+      }
+    ]
+  }
+}

.prettierrc

@@ -0,0 +1,10 @@
+{
+  "semi": true,
+  "singleQuote": true,
+  "trailingComma": "es5",
+  "printWidth": 100,
+  "tabWidth": 2,
+  "arrowParens": "avoid",
+  "jsxSingleQuote": false,
+  "jsxBracketSameLine": true
+}

package.json

@@ -21,11 +21,13 @@
     "predeploy": "npm run build",
     "deploy": "gh-pages -d build"
   },
-  "eslintConfig": {
-    "extends": [
-      "react-app",
-      "react-app/jest"
-    ]
+  "devDependencies": {
+    "eslint-config-airbnb": "^18.2.1",
+    "eslint-config-prettier": "^8.3.0",
+    "eslint-plugin-jsx-a11y": "^6.4.1",
+    "eslint-plugin-prettier": "^3.4.0",
+    "gh-pages": "^3.2.0",
+    "prettier": "^2.3.1"
   },
   "browserslist": {
     "production": [
@@ -38,8 +40,5 @@
       "last 1 firefox version",
       "last 1 safari version"
     ]
-  },
-  "devDependencies": {
-    "gh-pages": "^3.2.0"
   }
 }