fix: remove references to deprecated camelcase rule

[bbeesley]

Typescript eslint camelcase rule has now been removed in favour of the new naming-convention rule.
This change removes the reference to camelcase and replaces it with an equivalent naming-convention
rule.

fix #95

[bbeesley]

@iamturns lmk if there's anything you need me to amend here

[David-Else]

@iamturns I looked at the time it has taken in the past to update the Airbnb config on a major new ESLint airbnb/javascript#2223 and it can be months. Please merge this commit unless there is an objection. Thanks!

[bbeesley]

To be honest, I've been trying it out in another project and I can't exactly match the original camelcase rule, so it isn't going to be 100% compatible.

[David-Else]

@bbeesley Personally I don't care how accurate it is to the original, I would just like to get my lint setup running again without having to manually remove @typescript-eslint/camelcase

[iamturns]

Hey @bbeesley - thanks for the PR! I've started reviewing this evening, and your hunch is correct - I think there's more nuance we need to capture in the settings. As an example, this PR enforces camelCase on properties, which is something Airbnb specifically disables.
I've been scanning the Airbnb style guide and experimenting with different settings for @typescript-eslint/naming-convention. Getting closer, but I need to sign off for the evening. Will continue soon. Thanks again for the PR 👍

[iamturns]

Hey @bbeesley - have implemented this change in PR #99 . It required some different settings, and also disabling some other rules too.

Released as v8.0.0 now.

Thanks again for this PR which kicked this change forward 👏