Fix for typo in `corctl` and polishing GUI content.

Also updated git_refs after rewrite of openolt history to remove large
binary

Add deprecation notes regarding legacy gitbook toolchain, as links are
broken (cherry pick from fa9389b222cfcb25cb78d7b637ce035a6f82f89f).

Update docs to point to new Trellis documentation (cherry pick from
868f69d87978e171225d17f001b256b5f87e5973)

Change-Id: I90ccdaf8892e51c65fc14e7fd9495537db00b258
(cherry picked from commit 95eade026923f36642586c350a47823c4e483f60)
diff --git a/developer/contribute_to_the_docs.md b/developer/contribute_to_the_docs.md
index 8318116..0b9c2de 100644
--- a/developer/contribute_to_the_docs.md
+++ b/developer/contribute_to_the_docs.md
@@ -1,8 +1,8 @@
 # Contribute to the documentation
 
-> This tutorial assumes you already have [cloned the code](./getting_the_code.md),
-> [NodeJs](https://nodejs.org/en/) and the [Gitbook Toolchain](https://toolchain.gitbook.com/)
-> are installed.
+> This tutorial assumes you already have [cloned the
+> code](./getting_the_code.md), [NodeJs](https://nodejs.org/en/) and the legacy
+> Gitbook Toolchain (deprecated, docs unavailable) are installed.
 
 From a terminal window navigate to the documentation root:
 
diff --git a/git_refs b/git_refs
index d5e5e06..b3fec33 100644
--- a/git_refs
+++ b/git_refs
@@ -21,7 +21,7 @@
 kubernetes-service    /docs    3ea0a9c663059b3d8d5cb6609254a05f7fe72219
 olt-service           /docs    b9d725d7d46ed63f63d7cc7d32e149c0ed26a1c6
 onos-service          /docs    32b165a35c8a2779827d91269be5dbac8f3e0cea
-openolt               /        27939d8ed643293fd9f3a7ff4db95d9c0a972aed
+openolt               /        a4d6ba4eaa8d88760cfcd367921c91418b098b35
 openstack             /docs    f1897e0b6b0bb32dc6bc71ccbe21d87190359100
 rcord                 /docs    cd109155ec4d3172fb3d951a6e5c8dbc342e8885
 simpleexampleservice  /docs    ea2919f720a36f60aef284944db06725da503951
diff --git a/installation/fabric-setup.md b/installation/fabric-setup.md
index 65e61c8..613c7e0 100644
--- a/installation/fabric-setup.md
+++ b/installation/fabric-setup.md
@@ -3,11 +3,12 @@
 CORD uses the Trellis fabric to connect the data plane components together.
 This section describes how to setup the software for these switches.
 
-The latest [Trellis Fabric](https://wiki.opencord.org/display/CORD/Trellis%3A+CORD+Network+Infrastructure) documentation can be found on the CORD wiki.
+The latest documentation can be found on the [Trellis documentation
+site](https://docs.trellisfabric.org/).
 
 ## Supported Switches
 
-The list of supported hardware can be found in the [hardware requirements page](../prereqs/hardware.md).
+The list of supported hardware can be found in the [hardware requirements page](../prereqs/hardware.md)
 
 ## Operating System
 
diff --git a/overview.md b/overview.md
index 1a16dfb..f0d1ba8 100644
--- a/overview.md
+++ b/overview.md
@@ -51,7 +51,7 @@
 ## Making Changes to this Document
 
 The [http://guide.opencord.org](http://guide.opencord.org) website is built
-using the [GitBook Toolchain](https://toolchain.gitbook.com/), with the
+using the legacy GitBook Toolchain (deprecated, docs unavailable), with the
 documentation root in
 [docs](https://github.com/opencord/docs/blob/{{ book.branch }}) in a
 checked out source tree.  It is build with `make`, and requires that `gitbook`,
diff --git a/prereqs/hardware.md b/prereqs/hardware.md
index 6f1173e..e73ad48 100644
--- a/prereqs/hardware.md
+++ b/prereqs/hardware.md
@@ -46,11 +46,13 @@
 Following is a list of hardware that people from the ONF community
 have tested over time in lab trials.
 
+
 * **Compute Machines**
     * OCP Inspired™ QuantaGrid D51B-1U server. Each
     server is configured with 2x Intel E5-2630 v4 10C 2.2GHz 85W, 64GB of RAM 2133MHz DDR4, 2x 500GB HDD, and a 40 Gig adapter.
 
-* **Fabric Switches**
+* **Fabric Switches** - see also the [Trellis Documentation Supported
+  Hardware](https://docs.trellisfabric.org/supported-hardware.html)
     * **1G/10G** models (with 40G uplinks)
         * OCP Accepted™ EdgeCore AS5712-54X
         * OCP Accepted™ EdgeCore AS5812-54X
diff --git a/profiles/mcord/enodeb-setup.md b/profiles/mcord/enodeb-setup.md
index a1a7665..4f736e3 100644
--- a/profiles/mcord/enodeb-setup.md
+++ b/profiles/mcord/enodeb-setup.md
@@ -48,10 +48,9 @@
 
 `u32sgwipaddress`: SPGWU IP address on S1U interface.
 
-Where to get those IP addresses? As described at the end of the [M-CORD quick start
-page](https://guide.opencord.org/profiles/mcord/install.html), the command
-`openstack server list --all-projects` will list the VNFs and their IP
-addresses. For example, the
+Where to get those IP addresses? As described at the end of the [M-CORD quick
+start page](install.html), the command `openstack server list --all-projects`
+will list the VNFs and their IP addresses. For example, the
 `flat_network_s1mme` of MME VM is the `u32mmeipaddress`. The `flat_network_s1u`
 is the `u32sgwipaddress`.
 
diff --git a/profiles/seba/release-notes.md b/profiles/seba/release-notes.md
index 331645c..b77ed96 100644
--- a/profiles/seba/release-notes.md
+++ b/profiles/seba/release-notes.md
@@ -35,7 +35,7 @@
 
 A new command-line interface was created, `cordctl`, that administrators may use to manage
 the NEM. This tool provides an alternate interface to many of the functions that
-may also be done using the NEM GUI. `corctl` is written in the go programming language
+may also be done using the NEM GUI. `cordctl` is written in the go programming language
 and installs to an administrator's computer as a single binary.
 
 The NEM API was extended to provide additional data about versioning and database
@@ -79,12 +79,12 @@
 
 The following improvements were made to the GUI:
 
-* The GUI was improved to hide fields such as backend_status and policy_status for
+* Hidden fields such as backend_status and policy_status for
   models that do not require those fields.
 
-* Performance issues with Chrome browsers were resolved.
+* Resolved performance issues with Chrome browsers.
 
-* Issues with broken navigation between related models were resolved.
+* Resolved broken navigation between related models.
 
 ## SEBA-in-a-Box Improvements