Update docs for 2.1 release

Author: roji

doc/mapping/enum.md

@@ -1,8 +1,5 @@
 # Enum Type Mapping
 
-> [!NOTE]
-> This feature is only available in Npgsql EF Core 2.1, which is currently in preview.
-
 By default, any enum properties in your model will be mapped to database integers. EF Core 2.1 also allows you to map these to strings in the database with value converters.
 
 However, the Npgsql provider also allows you to map your CLR enums to [database enum types](https://www.postgresql.org/docs/current/static/datatype-enum.html). This option, unique to PostgreSQL, provides the best of both worlds: the enum is internally stored in the database as a number (minimal storage), but is handled like a string (more usable, no need to remember numeric values) and has type safety.

doc/mapping/full-text-search.md

@@ -1,8 +1,5 @@
 # Full Text Search
 
-> [!NOTE]
-> This feature is only available in Npgsql EF Core 2.1, which is currently in preview.
-
 PostgreSQL has [built-in support for full-text search](https://www.postgresql.org/docs/current/static/textsearch.html), which allows you to conveniently and efficiently query natural language documents.
 
 *TO BE COMPLETED*

doc/mapping/nodatime.md

@@ -1,8 +1,5 @@
 # Date/Time Mapping with NodaTime
 
-> [!NOTE]
-> This feature is only available in Npgsql EF Core 2.1, which is currently in preview.
-
 # What is NodaTime?
 
 By default, [the PostgreSQL date/time types](https://www.postgresql.org/docs/current/static/datatype-datetime.html) are mapped to the built-in .NET types (`DateTime`, `TimeSpan`). Unfortunately, these built-in types are flawed in many ways. The [NodaTime library](http://nodatime.org/) was created to solve many of these problems, and if your application handles dates and times in anything but the most basic way, you should consider using it. To learn more [read this blog post by Jon Skeet](http://blog.nodatime.org/2011/08/what-wrong-with-datetime-anyway.html).

doc/mapping/nts.md

@@ -1,8 +1,5 @@
 ## Spatial Mapping with NetTopologySuite
 
-> [!NOTE]
-> This feature is only available in Npgsql EF Core 2.1, which is currently in preview.
-
 PostgreSQL supports spatial data and operations via [the PostGIS extension](https://postgis.net/), which is a mature and feature-rich database spatial implementation. .NET doesn't provide a standard spatial library, but [NetTopologySuite](https://github.com/NetTopologySuite/NetTopologySuite) is quite a good candidate. The Npgsql EF Core provider has a plugin which allows you to map NetTopologySuite's types PostGIS columns, and even translate many useful spatial operations to SQL. This is the recommended way to interact with spatial types in Npgsql.
 
 Note that the EF Core NetTopologySuite plugin depends on [the Npgsql ADO.NET NetTopology plugin](http://www.npgsql.org/doc/types/nts.html), which provides NetTopologySuite support at the lower level. The EF Core plugin automatically arranged for the ADO.NET plugin to be set up.

doc/mapping/range.md

@@ -1,8 +1,5 @@
 # Range Type Mapping
 
-> [!NOTE]
-> This feature is only available in Npgsql EF Core 2.1, which is currently in preview.
-
 PostgreSQL has the unique feature of supporting [*range data types*](https://www.postgresql.org/docs/current/static/rangetypes.html). Ranges represent a range of numbers, dates or other data types, and allow you to easily query ranges which contain a value, perform set operations (e.g. query ranges which contain other ranges), and other similar operations. The range operations supported by PostgreSQL are listed [in this page](https://www.postgresql.org/docs/current/static/functions-range.html). Starting with version 2.1, the Npgsql EF Core provider allows you to seemlessly map PostgreSQL's built-in ranges, and even perform operations on them.
 
 Note that user-defined ranges are not supported.

doc/release-notes/2.1.md

@@ -1,13 +1,8 @@
 # 2.1 Release Notes
 
-> [!NOTE]
-> This version is still in preview
-
-<!--
 Version 2.1.0 of the Npgsql Entity Framework Core provider has been released and is available on nuget. This version works with [version 2.1.0 of Entity Framework Core](https://docs.microsoft.com/en-us/ef/core/what-is-new/ef-core-2.1), and contains some new Npgsql features as well.
--->
 
-Thanks to @austindrenski, @rwasef1830 for their valuable contributions.
+Thanks to @rwasef1830 and @austindrenski for their valuable contributions.
 
 ## New Features