NG: Refactored content about connectivity concerns to dedicated section

In order to maintain corresponding topics at a central place, no matter
whether they are concerned about CrateDB Cloud or CrateDB Self-Managed,
connectivity-, client- and integration-options have been refactored into
the canonical repository `crate-clients-tools`, which got a thorough
facelift with [1].

[1] crate/crate-clients-tools#33

CHANGES.rst

@@ -9,4 +9,6 @@ Unreleased
 - Consolidate ``cloud-reference``, ``cloud-howtos``, and ``cloud-tutorials``
 - Adjust links to accompany renaming to ``cloud-docs``
 - Adjust intersphinx references to accompany consolidation into single repository
-- Rename top-level directories to `howtos`, `reference`, and `tutorials`
+- Rename top-level directories to `howtos`, `reference`, and `tutorials`
+- Refactored content about connectivity concerns to dedicated section at
+  ``crate-client-tools``

docs/howtos/connect-to-cluster/index.md

@@ -0,0 +1,23 @@
+(connect-to-cluster-howto-index)=
+# Connect to your cluster
+
+We are maintaining a collection of how-to guides and tutorials about how to
+integrate with different applications, tools, libraries, extensions, and clients,
+that can be used to connect to your CrateDB Cloud cluster.
+
+
+::::{grid} 1 2 2 2
+:margin: 4 4 0 0
+:gutter: 1
+
+
+:::{grid-item-card} {material-outlined}`link;2em` Clients, Tools, and Integrations
+:link: crate-clients-tools:index
+:link-type: ref
+
+Learn about compatible client applications and tools, and how to configure
+your favorite client library to connect to a CrateDB cluster.
+:::
+
+
+::::