Title case consistency

[mdchia]

HyperKey should be capitalised as such in general documentation and the GUI, and in full lowercase in config files (as appropriate), the CLI command, and library imports.

Probably leave this as one of the last ctrl-F tasks (perhaps alongside a general cross check for typos and such once draft 1.0 documentation is done?)

[ChikithRishi]

• Just to confirm, should HyperKey (capital H and K) be used in the app name, UI, and documentation, while hyperkey remains consistently used in the CLI, config files, and library imports, as it already is? Currently, the UI says Hyperkey and the app name is hyperkey, I’ll update those accordingly after your confimation. @mdchia