Improve documentation

Author: jayqi

README.md

@@ -5,9 +5,9 @@
 [![tests](https://github.com/jayqi/sortedcontainers-pydantic/actions/workflows/tests.yml/badge.svg?branch=main)](https://github.com/jayqi/sortedcontainers-pydantic/actions/workflows/tests.yml?query=branch%3Amain)
 [![codecov](https://codecov.io/gh/jayqi/sortedcontainers-pydantic/branch/main/graph/badge.svg)](https://codecov.io/gh/jayqi/sortedcontainers-pydantic)
 
-This package adds [Pydantic](https://docs.pydantic.dev/latest/) support to [sortedcontainers](https://github.com/grantjenks/python-sortedcontainers/), a fast, pure-Python sorted collections library. 
+This package adds [Pydantic](https://docs.pydantic.dev/latest/) support to [sortedcontainers](https://github.com/grantjenks/python-sortedcontainers/), a fast, pure-Python library for sorted, mutable collections. 
 
-It implements [Pydantic's special methods](https://docs.pydantic.dev/latest/concepts/types/#customizing-validation-with-__get_pydantic_core_schema__) on sortedcontainer's `SortedDict`, `SortedList`, and `SortedSet` classes so that you can use them with Pydantic's models, validation, and serialization. To use, simply import the respective class from `sortedcontainers_pydantic` instead of `sortedcontainers`. 
+It implements [Pydantic's special methods](https://docs.pydantic.dev/latest/concepts/types/#customizing-validation-with-__get_pydantic_core_schema__) on subclasses of sortedcontainer's `SortedDict`, `SortedList`, and `SortedSet` classes so that you can use them with Pydantic's models, validation, and serialization. To use, simply import the respective class of the same name from `sortedcontainers_pydantic` instead of from `sortedcontainers`. 
 
 ```python
 from pydantic import BaseModel, TypeAdapter
@@ -19,6 +19,12 @@ class MyModel(BaseModel):
 MyModel(sorted_list=[3, 1, 2])
 #> MyModel(sorted_list=SortedList([1, 2, 3]))
 
+MyModel.model_validate_json('{"sorted_list": [3, 1, 2]}')
+#> MyModel(sorted_list=SortedList([1, 2, 3]))
+
+MyModel(sorted_list=[3, 1, 2]).model_dump_json()
+#> '{"sorted_list":[1,2,3]}'
+
 TypeAdapter(SortedList).validate_python([3, 1, 2])
 #> SortedList([1, 2, 3])
 
@@ -28,6 +34,12 @@ TypeAdapter(SortedList).validate_json("[3, 1, 2]")
 
 <sup>Reproducible example created by [reprexlite](https://github.com/jayqi/reprexlite) v0.5.0</sup>
 
+Currently, only Pydantic V2 is supported.
+
 ## Installation
 
-...
+sortedcontainers-pydantic is not yet available on PyPI. For now, install from GitHub:
+
+```bash
+pip install sortedcontainers-pydantic@git+https://github.com/jayqi/sortedcontainers-pydantic.git
+```