feat: implement scrollspy

package.json

@@ -33,7 +33,6 @@
     "@reach/router": "^1.3.3",
     "classnames": "^2.2.6",
     "gatsby": "^2.22.11",
-    "gatsby-plugin-anchor-links": "^1.1.1",
     "gatsby-plugin-google-fonts": "^1.0.1",
     "gatsby-plugin-layout": "^1.3.2",
     "gatsby-plugin-manifest": "^2.4.9",
@@ -57,6 +56,7 @@
     "react-highlight": "^0.12.0",
     "react-particles-js": "^3.2.1",
     "react-perfect-scrollbar": "^1.5.8",
+    "react-scrollspy": "^3.4.2",
     "styled-components": "^5.1.1",
     "typescript": "^3.9.3"
   },
@@ -72,6 +72,7 @@
     "@types/react": "^16.9.35",
     "@types/react-dom": "^16.9.8",
     "@types/react-helmet": "^6.0.0",
+    "@types/react-scrollspy": "^3.3.2",
     "@types/styled-components": "^5.1.0",
     "babel-plugin-polished": "^1.1.0",
     "babel-plugin-styled-components": "^1.10.7",