Improve semantic indentation rules to be more consistent with cljfmt

[rrudakov]

Example:

Before submitting a PR mark the checkboxes for the items you've done (if you
think a checkbox does not apply, then leave it unchecked):

• The commits are consistent with our contribution guidelines.
• You've added tests (if possible) to cover your change(s). Bugfix, indentation, and font-lock tests are extremely important!
• You've run M-x checkdoc and fixed any warnings in the code you've written.
• You've updated the changelog (if adding/changing user-visible functionality).
• You've updated the readme (if adding/changing user-visible functionality).

Thanks!

[bbatsov]

The proposal seems reasonable to me - from what I gather the essence here is that we want to treat differently forms depending on the position of their body/forms param.

Might be a good idea to mention this somewhere in the README, and I'm also wondering if we should make this configurable like in clojure-mode (there you can add extra forms to the various indentation categories, so you'd get consistent indentation for your macros as well).

Making this configurable is also need for CIDER to be able to insert indentation rules itself, based on forms indentation specs.

[rrudakov]

Thanks you for the review @bbatsov. I've refactored the code. It's less repetitive now and rules are customizable via clojure-ts-semantic-indent-rules variable. I also updated README. Please let me know what do you think.

[bbatsov]

Might be better to have several forms here, so it's clearer what the format is.

[bbatsov]

I think it'd be good to explain also the various block and inner values here, similar to how it's done in clojure-mode's docs.

[rrudakov]

I've adapted some examples from clojure-mode documentation and added some explanation about the rules.

[bbatsov]

Great work!