Add jiff entry in the features guide

guide/src/features.md

@@ -151,6 +151,19 @@ Adds a dependency on [hashbrown](https://docs.rs/hashbrown) and enables conversi
 
 Adds a dependency on [indexmap](https://docs.rs/indexmap) and enables conversions into its [`IndexMap`](https://docs.rs/indexmap/latest/indexmap/map/struct.IndexMap.html) type.
 
+### `jiff-01`
+
+Adds a dependency on [jiff](https://docs.rs/jiff/0.1)@0.1 and enables a conversion from [jiff](https://docs.rs/jiff)'s types to python:
+- [Span](https://docs.rs/jiff/0.1/jiff/struct.Span.html) -> [`PyDelta`]({{#PYO3_DOCS_URL}}/pyo3/types/struct.PyDelta.html)
+- [SignedDuration](https://docs.rs/jiff/0.1/jiff/struct.SignedDuration.html) -> [`PyDelta`]({{#PYO3_DOCS_URL}}/pyo3/types/struct.PyDelta.html)
+- [TimeZone](https://docs.rs/jiff/0.1/jiff/tz/struct.TimeZone.html) -> [`PyTzInfo`]({{#PYO3_DOCS_URL}}/pyo3/types/struct.PyTzInfo.html)
+- [Offset](https://docs.rs/jiff/0.1/jiff/tz/struct.Offset.html) -> [`PyTzInfo`]({{#PYO3_DOCS_URL}}/pyo3/types/struct.PyTzInfo.html)
+- [Date](https://docs.rs/jiff/0.1/jiff/civil/struct.Date.html) -> [`PyDate`]({{#PYO3_DOCS_URL}}/pyo3/types/struct.PyDate.html)
+- [Time](https://docs.rs/jiff/0.1/jiff/civil/struct.Time.html) -> [`PyTime`]({{#PYO3_DOCS_URL}}/pyo3/types/struct.PyTime.html)
+- [DateTime](https://docs.rs/jiff/0.1/jiff/civil/struct.DateTime.html) -> [`PyDateTime`]({{#PYO3_DOCS_URL}}/pyo3/types/struct.PyDateTime.html)
+- [Zoned](https://docs.rs/jiff/0.1/jiff/struct.Zoned.html) -> [`PyDateTime`]({{#PYO3_DOCS_URL}}/pyo3/types/struct.PyDateTime.html)
+- [Timestamp](https://docs.rs/jiff/0.1/jiff/struct.Timestamp.html) -> [`PyDateTime`]({{#PYO3_DOCS_URL}}/pyo3/types/struct.PyDateTime.html)
+
 ### `num-bigint`
 
 Adds a dependency on [num-bigint](https://docs.rs/num-bigint) and enables conversions into its [`BigInt`](https://docs.rs/num-bigint/latest/num_bigint/struct.BigInt.html) and [`BigUint`](https://docs.rs/num-bigint/latest/num_bigint/struct.BigUint.html) types.