Fix open typescript issues

[neozenith]

Related to #88 and #117

This project was converted from NodeJS to Typescript.

It transpiles correctly. However it was decided the open typecheck issues could be a separate issue. Dear reader… that why you find yourself here. 😊

They are summarised below:

The typescript errors can be summarised as follows:

• src/js/communities/Communities.tsx:

  • Preact component returns array - fine with preact but a problem for the types.
  • DOM element may be null.

• src/js/events/Meetup.tsx:

  • DOM element may be null
  • null handling of properties in event data (nullable properties defined as nullable if graphql schema doesn't say they're required)
  • Referencing property in event data that does not exist
  • indexing into object with numeric keys (map of day number to day name) with number (number is not assignable to 0 | 1 | 2 ....)

• src/js/main.ts:

  • function is not a constructor.

[neozenith]

This is addressed with #139