docs: document support for JDBC and pgx (#352)

* docs: document support for JDBC and pgx * docs: update documentation headers

Author: olavloite

README.md

@@ -5,8 +5,8 @@ equivalent for Spanner databases [that use the PostgreSQL interface](https://clo
 
 PGAdapter can be used with the following clients:
 1. `psql`: Versions 11, 12, 13 and 14 are supported. See [psql support](docs/psql.md) for more details.
-2. `JDBC`: Versions 42.x and higher have __experimental support__. See [JDBC support](docs/jdbc.md) for more details.
-3. `pgx`: Version 4.15 and higher have __experimental support__. See [pgx support](docs/pgx.md) for more details.
+2. `JDBC`: Versions 42.x and higher are supported. See [JDBC support](docs/jdbc.md) for more details.
+3. `pgx`: Version 4.15 and higher are supported. See [pgx support](docs/pgx.md) for more details.
 4. `psycopg2`: Version 2.9.3 and higher (but not `psycopg3`) have __experimental support__.
  See [psycopg2](docs/psycopg2.md) for more details. PGAdapter has not yet been tested with `psycopg3`.
 

docs/jdbc.md

@@ -1,7 +1,6 @@
-# Google Cloud Spanner PGAdapter - JDBC Experimental Support
+# PGAdapter - JDBC Connection Options
 
-PGAdapter has __experimental support__ for the [PostgreSQL JDBC driver](https://github.com/pgjdbc/pgjdbc)
-version 42.0.0 and higher.
+PGAdapter supports the [PostgreSQL JDBC driver](https://github.com/pgjdbc/pgjdbc) version 42.0.0 and higher.
 
 ## Usage
 

docs/pgx.md

@@ -1,7 +1,6 @@
-# Google Cloud Spanner PGAdapter - pgx Experimental Support
+# PGAdapter - pgx Connection Options
 
-PGAdapter has __experimental support__ for the [Go pgx driver](https://github.com/jackc/pgx)
-version 4.15.0 and higher. 
+PGAdapter supports the [Go pgx driver](https://github.com/jackc/pgx) version 4.15.0 and higher. 
 
 ## Usage