Driver/Crystal: Add dedicated page

Author: amotl

docs/_assets/icon/crystal-logo.svg

@@ -0,0 +1,46 @@
+(connect-crystal)=
+
+# Crystal
+
+:::{div} sd-text-muted
+Connect to CrateDB from Crystal applications.
+:::
+
+:::{rubric} About
+:::
+
+[crystal-pg] is a native, non-blocking Postgres driver for Crystal,
+building upon [crystal-db].
+
+:::{rubric} Synopsis
+:::
+
+`shard.yml`
+```yaml
+dependencies:
+  pg:
+    github: will/crystal-pg
+```
+```shell
+shards install
+```
+`example.cr`
+```crystal
+require "db"
+require "pg"
+
+DB.open("postgres://crate:crate@localhost:5432/doc?sslmode=disable") do |db|
+
+  db.query "SELECT mountain, height FROM sys.summits ORDER BY height DESC LIMIT 3" do |rs|
+    puts "#{rs.column_name(0)} (#{rs.column_name(1)})"
+    rs.each do
+      puts "#{rs.read(String)}: (#{rs.read(Int32)})"
+    end
+  end
+
+end
+```
+
+
+[crystal-db]: https://github.com/crystal-lang/crystal-db
+[crystal-pg]: https://github.com/will/crystal-pg

docs/connect/crystal.md

@@ -49,6 +49,20 @@ CrateDB drivers and adapters for supported programming languages, frameworks, an
 :margin: 4 4 0 0
 :padding: 0
 
+::::{grid-item-card} Crystal
+:link: connect-crystal
+:link-type: ref
+:link-alt: Connect to CrateDB using Crystal
+:padding: 3
+:text-align: center
+:class-card: sd-pt-3
+:class-body: sd-fs-1
+:class-title: sd-fs-6
+```{image} /_assets/icon/crystal-logo.svg
+:height: 70px
+```
+::::
+
 ::::{grid-item-card} Java
 :link: connect-java
 :link-type: ref
@@ -182,6 +196,7 @@ application
 :maxdepth: 1
 :hidden:
 
+crystal
 java
 javascript
 php