Add a11y information

[jdjuan]

Add ACCESSIBILITY section in the website describing the options available in the conference. Routes. Ramps. Bathrooms. In general for people with disabilities

https://twitter.com/ellenfromnowon/status/846011542776754183
https://nineworlds.co.uk/access
https://belfasttrans.org.uk/access/

If you are organising events in your spare time don’t stress too much about trying to act on all of these at once. Take on what you can handle and slowly build it up to make your event the best it can be.