The headings are messed up in the README.md - missing space

A space is missing between the last hash (`#`) and the heading name, on at least five of the headings in the read me:

> #Firmata
>
> ...
>
> ##Usage
>
> ...
>
> ##Firmata Client Libraries

... and so on.

Obviously it should be

> # Firmata
>
> ...
>
> ## Usage
>
> ...
>
> ## Firmata Client Libraries

It just makes reading the readme, especially for the uninitiated, a little difficult at first - plus it gives the page an "unpolished" look, if you don't mind me saying..

Open README.md and inspect the headings identified in the issue, including Firmata, Usage, and Firmata Client Libraries. Add the missing spaces after each leading hash sequence, then preview the rendered README to confirm the headings display correctly.

Written by the indexing model from the issue text.