[Docs] clean up readme code

Author: ljharb

readme.markdown

@@ -11,11 +11,11 @@ synchronously
 
 asynchronously resolve:
 
-``` js
+```js
 var resolve = require('resolve');
 resolve('tap', { basedir: __dirname }, function (err, res) {
-    if (err) console.error(err)
-    else console.log(res)
+    if (err) console.error(err);
+    else console.log(res);
 });
 ```
 
@@ -26,7 +26,7 @@ $ node example/async.js
 
 synchronously resolve:
 
-``` js
+```js
 var resolve = require('resolve');
 var res = resolve.sync('tap', { basedir: __dirname });
 console.log(res);
@@ -39,8 +39,8 @@ $ node example/sync.js
 
 # methods
 
-``` js
-var resolve = require('resolve')
+```js
+var resolve = require('resolve');
 ```
 
 ## resolve(id, opts={}, cb)
@@ -79,11 +79,11 @@ This is the way Node resolves dependencies when executed with the [--preserve-sy
 
 default `opts` values:
 
-``` javascript
+```js
 {
     paths: [],
     basedir: __dirname,
-    extensions: [ '.js' ],
+    extensions: ['.js'],
     readFile: fs.readFile,
     isFile: function isFile(file, cb) {
         fs.stat(file, function (err, stat) {
@@ -134,11 +134,11 @@ This is the way Node resolves dependencies when executed with the [--preserve-sy
 
 default `opts` values:
 
-``` javascript
+```js
 {
     paths: [],
     basedir: __dirname,
-    extensions: [ '.js' ],
+    extensions: ['.js'],
     readFileSync: fs.readFileSync,
     isFile: function isFile(file) {
         try {
@@ -152,7 +152,7 @@ default `opts` values:
     moduleDirectory: 'node_modules',
     preserveSymlinks: false
 }
-````
+```
 
 ## resolve.isCore(pkg)
 
@@ -162,7 +162,7 @@ Return whether a package is in core.
 
 With [npm](https://npmjs.org) do:
 
-```
+```sh
 npm install resolve
 ```