feat: add bson ObjectId impl

[ShaunSHamilton]

Goal

The docs suggest the bson-uuid-impl feature flag implements types from bson. However, this is misleading, because it just implements TS for bson::Uuid.

On top of this, the library suggests there is a bson feature flag. However, enabling this does nothing. So, this pr adds an impl for bson::oid::ObjectId which is a particularly common type.

This PR does not expect to implement every exported type from bson. Hopefully, this will be done in future releases of ts-rs.

Related to #186

Changes

• Added bson::oid::ObjectId impl under bson feature config.
• Changed lib docs about bson feature flag

Checklist

• I have followed the steps listed in the Contributing guide.
• If necessary, I have added documentation related to the changes made.
• I have added or updated the tests related to the changes made.

Notes

The docs suggest running cargo +nightly fmt. However, after running this, unrelated files were changed. So, those have not been pushed.

bson serializes ObjectId into { "$oid": <string> }. However, this is likely not what users want in their types.