docs: fix typos (puppeteer#1647)

CONTRIBUTING.md

@@ -63,7 +63,7 @@ footer
     - `docs` - changes to docs, e.g. `docs(api.md): ..` to change documentation
     - `test` - changes to puppeteer tests infrastructure
     - `style` - puppeteer code style: spaces/alignment/wrapping etc
-    - `chore` - build-related work, e.g. doclint changes / travis / appveyour
+    - `chore` - build-related work, e.g. doclint changes / travis / appveyor
 1. *namespace* is put in parenthesis after label and is optional
 2. *title* is a brief summary of changes
 3. *description* is **optional**, new-line separated from title and is in present tense

examples/README.md

@@ -31,7 +31,7 @@ const browser = await puppeteer.launch({
 - [Puppetron](https://github.com/cheeaun/puppetron) - Demo site that shows how to use Puppeteer and Headless Chrome to render pages. Inspired by [GoogleChrome/rendertron](https://github.com/GoogleChrome/rendertron).
 - [Thal](https://medium.com/@e_mad_ehsan/getting-started-with-puppeteer-and-chrome-headless-for-web-scrapping-6bf5979dee3e "An article on medium") - Getting started with Puppeteer and Chrome Headless for Web Scraping.
 - [pupperender](https://github.com/LasaleFamine/pupperender) - Express middleware that checks the User-Agent header of incoming requests, and if it matches one of a configurable set of bots, render the page using Puppeteer. Useful for PWA rendering.
-- [headless-chrome-crawler](https://github.com/yujiosaka/headless-chrome-crawler) - Crawler that provides simple APIs to manupluate Headless Chrome and allows you to crawl dynamic websites.
+- [headless-chrome-crawler](https://github.com/yujiosaka/headless-chrome-crawler) - Crawler that provides simple APIs to manipulate Headless Chrome and allows you to crawl dynamic websites.
 
 ## Testing
 - [angular-puppeteer-demo](https://github.com/Quramy/angular-puppeteer-demo) - Demo repository explaining how to use Puppeteer in Karma.