doc: write about tt-connect and direct terminals (#5654)

* doc: write about tt-connect and direct terminals

Author: maryiaLichko

doc/tooling/tcm/index.rst

@@ -47,4 +47,5 @@ to read data. LDAP authorization is supported as well.
     tcm_dev_mode
     tcm_configuration_reference
     tcm_integrity_check
+    tcm_terminals
     Releases <tcm_releases/index>

doc/tooling/tcm/tcm_terminals.rst

@@ -0,0 +1,40 @@
+..  _tcm_terminals:
+
+Terminals
+=========
+
+|tcm_full_name| (TCM) provides two ways to interact with Tarantool instances:
+
+-  ``direct`` — a terminal that connects directly to a Tarantool instance using the `go-tarantool <https://github.com/tarantool/go-tarantool/>`__ library, bypassing the `tt connect` utility
+-  ``tt-connect`` — a terminal that uses the :ref:`tt-cli` utility to connect to a Tarantool instance
+
+Both terminals allow executing SQL queries, managing cluster state, viewing metrics, and more.
+
+..  _tcm_terminals_direct:
+
+Terminal direct
+---------------
+
+Authentication credentials are taken from the cluster configuration:
+
+..  code-block:: yaml
+
+    credentials:
+      users:
+        tcm_tarantool:
+          password: tcm_tarantool_password
+          roles: [super]
+
+
+..  _tcm_terminals_tt-connect:
+
+Terminal tt-connect
+-------------------
+
+Specify the path to the tt connect utility in the tcm.yaml configuration file:
+
+..  code-block:: yaml
+
+    mode: production
+    cluster:
+      tt-command: .tarantool/tt

doc/tooling/tcm/tcm_ui_overview.rst

@@ -173,14 +173,17 @@ The instance page opens when you click an instance name on the **Stateboard**.
 
 It provides a set of tabs for performing actions on the selected Tarantool instance:
 
--   **Details** and **State** tabs: view instance details as a human-readable table
+*   **Details** and **State** tabs: view instance details as a human-readable table
     or as a console output of ``box.cfg``, ``box.info``, and other built-in functions
--   **SQL** and **Terminal** tabs: run SQL and Lua commands on the instance
--   **Logs** tab: view instance logs
--   **Slabs** tab: view :ref:`slab allocator <memtx-memory>` statistics
--   **Users** tab: manage Tarantool :ref:`users and roles <tcm_cluster_users>` on the instance
--   **Funcs**: manage and call stored functions
--   **Metrics**: view instance metrics
+*   **SQL** and **Terminal** tabs: run SQL and Lua commands on the instance. TCM provides :ref:`two ways <tcm_terminals>` to interact with Tarantool instances:
+
+    -   ``direct`` — a terminal that connects directly to a Tarantool instance using the `go-tarantool <https://github.com/tarantool/go-tarantool/>`__ library, bypassing the tt connect utility
+    -   ``tt-connect`` — a terminal that uses the :ref:`tt-cli` utility to connect to a Tarantool instance
+*   **Logs** tab: view instance logs
+*   **Slabs** tab: view :ref:`slab allocator <memtx-memory>` statistics
+*   **Users** tab: manage Tarantool :ref:`users and roles <tcm_cluster_users>` on the instance
+*   **Funcs**: manage and call stored functions
+*   **Metrics**: view instance metrics
 
 The instance page has an **Actions** menu at the top that allows you to: