[Docs]: The pytket encoder/decoder needs better docs

[aborgna-q]

Documentation Type

Missing documentation

Documentation Location

tket::serialize::pytket docs

Issue Description

Some broken / confusing encoder / decoder docs:

• tket2/tket/src/serialize/pytket/config/decoder_config.rs

  Lines 68 to 71 in 9df9993

  	/// Encode a HUGR operation using the registered custom encoders.
  	///
  	/// Returns `true` if the operation was successfully converted and no further
  	/// encoders should be called.

  Mentions encoding, should be decoding?

• tket2/tket/src/serialize/pytket/extension.rs

  Lines 116 to 126 in 9df9993

  	/// operation and add it to the pytket decoder.
  	///
  	/// Returns an [`DecodeStatus`] indicating if the operation was successfully
  	/// converted. If the operation is not supported by the decoder, it's
  	/// important to **not** modify the `decoder` context as that may invalidate
  	/// the context for other decoders that may be called afterwards.
  	///
  	/// `op` will always have one of the [`tket_json_rs::OpType`]s specified in
  	/// [`PytketDecoder::op_types`].
  	fn op_to_hugr<'h>(
  	&self,

  First paragraph also seems like it references encoding, but not sure?

• tket2/tket/src/serialize/pytket/decoder.rs

  Lines 544 to 545 in 60ce5e2

  	/// Add a tket1 [`circuit_json::Command`] from the serial circuit to the
  	/// decoder.

  Mentions tket1 instead of pytket (mentioned everywhere else afaik), and as a driveby could (probably) fit on a single line

And as you said it may be useful to have a more general intro to the encoder / decoder framework.

Suggested Improvement

No response

Additional Context

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