docs: document node-postgres support (#489)

* docs: document node-postgres support * docs: update node-postgres support * docs: document untyped parameters behavior

Author: olavloite

README.md

@@ -9,8 +9,7 @@ PGAdapter can be used with the following drivers and clients:
 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`) are supported. See [psycopg2](docs/psycopg2.md) for more details.
-5. `node-postgres`: Version 8.8.0 and higher have __experimental support__.
- See [node-postgres support](docs/node-postgres.md) for more details.
+5. `node-postgres`: Version 8.8.0 and higher are supported. See [node-postgres support](docs/node-postgres.md) for more details.
 
 ## Frameworks
 PGAdapter can be used with the following frameworks:

docs/node-postgres.md

@@ -1,7 +1,6 @@
-# Google Cloud Spanner PGAdapter - node-postgres Experimental Support
+# PGAdapter - node-postgres Connection Options
 
-PGAdapter has __experimental support__ for the [node-postgres driver](https://node-postgres.com/)
-version 8.8.0 and higher.
+PGAdapter supports the [node-postgres driver](https://node-postgres.com/) version 8.8.0 and higher.
 
 ## Usage
 
@@ -116,3 +115,8 @@ console.log(res);
 ```
 
 ## Limitations
+- `node-postgres` always uses untyped query parameters encoded as strings. Cloud Spanner requires
+ query parameters to be typed. PGAdapter therefore infers the types of the query parameters the
+ first time it sees a given SQL string by analyzing the SQL statement and caching the result on the
+ connection. This means that the first execution of a SQL statement with query parameters on a
+ connection will be slightly slower than the following executions.