Merge 'doc: remove the dead link to unirestore' from Anna Stuchlik

Fixes #14459

This PR removes the (dead) link to the unirestore tool in a private repository. In addition, it adds minor language improvements.

Closes #14519

* github.com:scylladb/scylladb:
  doc: minor language improvements on the Migration Tools page
  doc: remove the link to the private repository

docs/using-scylla/mig-tool-review.rst

@@ -2,12 +2,12 @@
 ScyllaDB Migration Tools: An Overview
 =======================================
 
-The following migration tools are available for migrating to Scylla from Compatible databases, like Apache Cassandra or other Scylla Clusters (Open Source or Enterprise):
+The following migration tools are available for migrating to ScyllaDB from compatible databases, 
+such as Apache Cassandra, or from other Scylla clusters (ScyllaDB Open Source or Enterprise):
 
 * From SSTable to SSTable
-    - Based on Scylla refresh
+    - Based on ScyllaDB refresh
     - On a large scale, it requires tooling to upload / transfer files from location to location.
-    - For example, `unirestore <https://github.com/scylladb/field-engineering/tree/master/unirestore>`_: SSTable to SSTable
 * From SSTable to CQL.
     - :doc:`sstableloader</operating-scylla/admin-tools/sstableloader/>`
 * From CQL to CQL