docs: update docs

refs: #3670

Change-Id: I4a90df1cf5b28d05fd81877bf4d51659e21b1119
diff --git a/docs/GUI.md b/docs/GUI.md
index a465269..b190eeb 100644
--- a/docs/GUI.md
+++ b/docs/GUI.md
@@ -13,21 +13,21 @@
 
 There are two file formats used by Mini-NDN edit.
 
-* ``.mnndn`` files store topology information used by the GUI. Mini-NDN Edit can open and
-save ``.mnndn`` files.
+* `.mnndn` files store topology information used by the GUI. Mini-NDN Edit can open and
+save `.mnndn` files.
 
-* ``.conf`` files are used by Mini-NDN to create and run topologies. Mini-NDN Edit can generate a
-``.conf`` file from a ``.mnndn`` file. Mini-NDN edit cannot open ``.conf`` files. Please see
-[CONFIG-FILE.md](CONFIG.md) for more information on the content and format of ``.conf`` files.
+* `.conf` files are used by Mini-NDN to create and run topologies. Mini-NDN Edit can generate a
+`.conf` file from a `.mnndn` file. Mini-NDN edit cannot open `.conf` files. Please see
+[CONFIG-FILE.md](CONFIG.md) for more information on the content and format of `.conf` files.
 
 #### File menu
 
 ![file-dropdown](img/gui/file-dropdown.png)
 
 * **New** - Erase the current canvas and provide a new empty topology
-* **Open** - Open a ``.mnndn`` topology file
-* **Save** - Save the current topology as a ``.mnndn`` topology file
-* **Generate** - Convert the current topology to a ``.conf`` file runnable by Mini-NDN
+* **Open** - Open a `.mnndn` topology file
+* **Save** - Save the current topology as a `.mnndn` topology file
+* **Generate** - Convert the current topology to a `.conf` file runnable by Mini-NDN
 * **Run** - Run the current topology in Mini-NDN. The GUI will disappear and Mini-NDN will run on
             the command-line.
 * **Quit** - Exit Mini-NDN edit
@@ -38,7 +38,7 @@
 ![cursor-tool](img/gui/cursor-tool.png)
 
 The *cursor tool* is used to select and move nodes in the topology. A selected node or link can be
-removed from the topology using the ``backspace`` key or by selecting ``edit/cut``.
+removed from the topology using the `backspace` key or by selecting `edit/cut`.
 
 ### Host tool
 ![host-tool](img/gui/host-tool.png)
@@ -63,7 +63,7 @@
 #### Editing host information
 
 To edit a host's information and configuration, right-click on the desired node and select
-``Host Options``.
+`Host Options`.
 
 The *Host Options* window will include tabs to modify the node's properties as well as the
 configuration files for NFD and NLSR on that node.
@@ -74,7 +74,7 @@
 
 #### Editing link configuration
 
-To edit a link's configuration, right-click on the desired link and select ``Link Options``.
+To edit a link's configuration, right-click on the desired link and select `Link Options`.
 
 The *Link Options* window will allow configuration of the link's bandwidth, delay, and loss rate.