Fix formatting of example blocks

With the new stylesheet example blocks (delimited with ====) are
rendered as rather intrusive boxes with large padding in yellow
and grey.

This patch replaces the example blocks with simple code blocks
(delimited with ----) that better match the overall style of the
documentation.

Change-Id: Id95387cdb153332c2066e2d5e378697647dbca52
Signed-off-by: Michael Ochmann <michael.ochmann@sap.com>
diff --git a/Documentation/cmd-plugin-install.txt b/Documentation/cmd-plugin-install.txt
index e701f98..274b446 100644
--- a/Documentation/cmd-plugin-install.txt
+++ b/Documentation/cmd-plugin-install.txt
@@ -45,31 +45,31 @@
 == EXAMPLES
 Install a plugin from an absolute file path on the server's host:
 
-====
+----
 	ssh -p 29418 localhost gerrit plugin install -n name.jar \
 	  $(pwd)/my-plugin.jar
-====
+----
 
 Install a WebUi plugin from an absolute file path on the server's host:
 
-====
+----
   ssh -p 29418 localhost gerrit plugin install -n name.js \
     $(pwd)/my-webui-plugin.js
-====
+----
 
 Install a plugin from an HTTP site:
 
-====
+----
 	ssh -p 29418 localhost gerrit plugin install -n name.jar \
 	  http://build-server/output/our-plugin
-====
+----
 
 Install a plugin from piped input:
 
-====
+----
 	ssh -p 29418 localhost gerrit plugin install -n name.jar \
 	  - <target/name-0.1.jar
-====
+----
 
 GERRIT
 ------