Add missing dependency, update base URI

Add @reach/slider because build encounters errors.

Also add base URI to correct paths.

doczrc.js

@@ -1,3 +1,4 @@
 export default {
   typescript: true,
+  base: '/tesseract/web/react/common',
 }

package.json

@@ -45,6 +45,7 @@
     "docs": "docz"
   },
   "dependencies": {
+    "@reach/slider": "^0.10.5",
     "docz": "^2.3.1",
     "pascal-case": "3.1.1",
     "prop-types": "15.7.2",