Add awesome_bot link validation

[davidstaheli]

This PR:

1. Fixes broken or redirecting links to pass awesome_bot validation.
2. Adds azure-pipelines.yml that can run awesome_bot in an Azure Pipelines build.

I tested the build succeeding as is, and failing if a link gets out of line.

If/when this PR gets merged into master, to create a CI pipeline for this repo:

1. Install the Azure Pipelines GitHub App into the johnpapa GitHub organization, during which:
   1. When redirected to Azure Pipelines to finish setup, sign in with the credentials you use for dev.azure.com/johnpapa or johnpapa.visualstudio.com.
   2. When asked to choose an org & project, choose the "johnpapa" org and click the link to create a new project named "angular-styleguide".
   3. On the "New pipeline - Select repository" page, choose this johnpapa/angular-styleguide repo:
   4. Click Run to use the existing YAML file in the repo: azure-pipelines.yml:
   5. You now have a public CI pipeline that will run for PRs targeting the master branch.

After this, you can add a build status badge to the top of your README.md by pasting in Markdown as described here.

[davidstaheli]

JFYI @johnpapa