Add caching section to README.md

README.md

@@ -20,6 +20,7 @@ This gem was extracted from [EveMonk](https://evemonk.com). Source code of EveMo
 * [Usage](#usage)
 * [Useful links](#useful-links)
 * [Development](#development)
+* [Caching](#caching)
 * [Contributing](#contributing)
 * [Author](#author)
 * [Contributors](#contributors)
@@ -3086,6 +3087,10 @@ After checking out the repo, run `bin/setup` to install dependencies. Then, run
 
 To install this gem onto your local machine, run `bundle exec rake install`. To release a new version, update the version number in `version.rb`, and then run `bundle exec rake release`, which will create a git tag for the version, push git commits and tags, and push the `.gem` file to [rubygems.org](https://rubygems.org).
 
+## Caching
+
+TODO
+
 ## Contributing
 
 Issue reports and pull requests are welcome on GitHub at <https://github.com/evemonk/eve_online>.