syntax highlight + TOC scroll + other content parsing improvements

package.json

@@ -35,6 +35,7 @@
     "bluebird": "^3.4.1",
     "body-parser": "^1.15.2",
     "bulma": "^0.1.2",
+    "cheerio": "^0.20.0",
     "compression": "^1.6.2",
     "connect-flash": "^0.1.1",
     "connect-redis": "^3.1.0",
@@ -44,6 +45,7 @@
     "express-brute-redis": "0.0.1",
     "express-session": "^1.14.0",
     "express-validator": "^2.20.8",
+    "highlight.js": "^9.6.0",
     "i18next": "^3.4.1",
     "i18next-express-middleware": "^1.0.1",
     "i18next-node-fs-backend": "^0.1.2",
@@ -53,6 +55,7 @@
     "markdown-it": "^7.0.1",
     "markdown-it-abbr": "^1.0.3",
     "markdown-it-anchor": "^2.5.0",
+    "markdown-it-attrs": "^0.6.3",
     "markdown-it-emoji": "^1.2.0",
     "markdown-it-expand-tabs": "^1.0.11",
     "markdown-it-external-links": "0.0.5",
@@ -71,6 +74,7 @@
     "serve-favicon": "^2.3.0",
     "simplemde": "^1.11.2",
     "slug": "^0.9.1",
+    "sticky-js": "^1.0.5",
     "twemoji-awesome": "^1.0.4",
     "validator": "^5.5.0",
     "validator-as-promised": "^1.0.2",