docs: add example usage

README.md

@@ -31,3 +31,60 @@ log events that can be consumed by a listener on the process object.
   the consumer to stop printing messages.
 * `log.resume(...args)` calls `process.emit('log', 'resume', ...args)`
   Used to tell the consumer that it is ok to print messages again.
+* `log.LEVELS` an array of strings of all log method names
+
+## Examples
+
+Every method calls `process.emit('log', level, ...otherArgs)` internally.
+So in order to consume those events you need to do `process.on('log', fn)`.
+
+### Colorize based on level
+
+Here's an example of how to consume `proc-log` events and colorize them
+based on level:
+
+```js
+const chalk = require('chalk')
+
+process.on('log', (level, ...args) => {
+  if (level === 'error') {
+    console.log(chalk.red(level), ...args)
+  } else {
+    console.log(chalk.blue(level), ...args)
+  }
+})
+```
+
+### Pause and resume
+
+`pause` and `resume` are included so you have the ability to tell your consumer
+that you want to pause or resume your display of logs. In the npm CLI we use
+this to buffer all logs on init until we know the correct loglevel to display.
+But we  also setup a second handler that writes everything to a file even if
+paused.
+
+```js
+let paused = true
+const buffer = []
+
+// this handler will buffer and replay logs only
+// after `procLog.resume()` is called
+process.on('log', (level, ...args) => {
+  if (level === 'resume') {
+    buffer.forEach((item) => console.log(...item))
+    paused = false
+    return
+  } 
+
+  if (paused) {
+    buffer.push([level, ...args])
+  } else {
+    console.log(level, ...args)
+  }
+})
+
+// this handler will write everything to a file
+process.on('log', (...args) => {
+  fs.appendFileSync('debug.log', args.join(' '))
+})
+```