Update docs pipeline to solidity-docgen@0.6 (#3707)

scripts/gen-nav.js

@@ -1,14 +1,12 @@
 #!/usr/bin/env node
 
 const path = require('path');
-const proc = require('child_process');
+const glob = require('glob');
 const startCase = require('lodash.startcase');
 
 const baseDir = process.argv[2];
 
-const files = proc.execFileSync(
-  'find', [baseDir, '-type', 'f'], { encoding: 'utf8' },
-).split('\n').filter(s => s !== '');
+const files = glob.sync(baseDir + '/**/*.adoc').map(f => path.relative(baseDir, f));
 
 console.log('.API');