docs: Update Parquet readme implementation status (#8731)

# Which issue does this PR close?


# Rationale for this change

We now have a nice centralized location for parquet implementation
status on the Apache Parquet site, so let's direct users there rather
than maintain a separate copy here
- https://parquet.apache.org/docs/file-format/implementationstatus/

# What changes are included in this PR?

1. Remove existing implementation status
2. Add link to the parquet site

# Are these changes tested?

We typically require tests for all PRs in order to:
1. Prevent the code from being accidentally broken by subsequent changes
4. Serve as another way to document the expected behavior of the code

If tests are not included in your PR, please explain why (for example,
are they covered by existing tests)?

# Are there any user-facing changes?

If there are user-facing changes then we may require documentation to be
updated before approving the PR.

If there are any breaking changes to public APIs, please call them out.

Author: alamb

parquet/README.md

@@ -73,23 +73,10 @@ The `parquet` crate provides the following features which may be enabled in your
 
 ## Parquet Feature Status
 
-- [x] All encodings supported
-- [x] All compression codecs supported
-- [x] Read support
-  - [x] Primitive column value readers
-  - [x] Row record reader
-  - [x] Arrow record reader
-  - [x] Async support (to Arrow)
-  - [x] Encrypted files
-- [x] Statistics support
-- [x] Write support
-  - [x] Primitive column value writers
-  - [ ] Row record writer
-  - [x] Arrow record writer
-  - [x] Async support
-  - [x] Encrypted files
-- [x] Predicate pushdown
-- [x] Parquet format 4.0.0 support
+Please see the [Implementation Status Page] on the [Apache Parquet] website for
+information on the status of this implementation.
+
+[implementation status page]: https://parquet.apache.org/docs/file-format/implementationstatus/
 
 ## License