To add twitter timelines or searches to a page, we need to create a twitter widget.  To do this goto publish.twitter.com and past in the URL of feed you'd like to embed. 
e.g. https://twitter.com/TwitterDev

You'll end up with a piece of code like:

<a class="twitter-timeline" href="https://twitter.com/TwitterDev">Tweets by TwitterDev</a> <script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script>

• Copy it using "Ctrl+C", and return to T4.
• Add a 'Raw HTML/Javascript' type, where you would like the feed to embed
• Paste the code into that and Update/Approve the content.

Further info:

An overview of embedding Twitter timelines is available, detailing customisations.  Information on embedding twitter, maps, audio, video and other media files can be found on our T4 support blog.

Changing the width of your embedded content will adjust the size of the text  e.g.

<a class="twitter-timeline"
  href="https://twitter.com/TwitterDev"
  data-width="300"
  data-height="300">
Tweets by @TwitterDev
</a>

Has smaller text than:

<a class="twitter-timeline"
  href="https://twitter.com/TwitterDev"
  data-width="600"
  data-height="300">
Tweets by @TwitterDev
</a>