insert install instructions (taken from the MR) and link to MR

OPPO_FIND_7a_(oppo-find-7a).mw

@@ -64,13 +64,7 @@ Is OTG available, not used in wiki
 == How to enter flash mode ==
 
 == Installation ==
-<!-- add more sections below as necessary, e.g. Wifi, photos, ... -->
+Install the image to an sd card and flash the boot.img to the device.
 
 == See also ==
-<!--
-Link to related gitlab issues or merge requests like the following (replace CHANGEME with the ID, e.g. 1234):
-* {{MR|CHANGEME|pmaports}} Initial merge request
-* {{issue|CHANGEME|pmaports}} Some related issue
-You can also add normal web links:
-* [https://redmine.replicant.us/projects/replicant/wiki/GalaxyS2I9100 Replicant wiki page]
--->
+* {{MR|357|pmaports}} Initial merge request