Revise CGM customization details for xDrip4iOS (#1034)

* Revise CGM customization details for xDrip4iOS

Updated information about customizing Loop with xDrip4iOS and clarified installation instructions.

* fix typo

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Co-authored-by: marionbarker <marionbarker@earthlink.net>

Author: carolvchn

docs/faqs/cgm-faqs.md

@@ -122,7 +122,7 @@ There are a number of *Libre* sensors in which the only option for digital acces
 
 **The use of *LibreLinkUp* requires internet access via WiFi or Cell service.**
 
-If this is your only option for CGM, evaluate whether you want to add xDrip4iOS as a CGM option. Instructions for this customization are found at [Loop and Learn: Add CGM to Loop](https://www.loopandlearn.org/custom-code-add-cgm-pump/). The reason to recommend this option is that xDrip4iOS can sense when the *Libre* transmits glucose readings to your phone, although it cannot read the glucose value. Shortly thereafter, it will request the CGM reading from *LibreLinkUp*.
+If this is your only option for CGM, evaluate whether you want to add xDrip4iOS as a CGM option. Information about this customization is found at [Loop and Learn: Add xDrip4iOS Client to Loop](https://www.loopandlearn.org/custom-code/#add-cgm-client)); it is installed using the Customization Select Script. The reason to recommend this option is that xDrip4iOS can sense when the *Libre* transmits glucose readings to your phone, although it cannot read the glucose value. Shortly thereafter, it will request the CGM reading from *LibreLinkUp*.
 
 If you prefer not to customize Loop, then you can configure [Nightscout](https://nightscout.github.io/uploader/uploaders/#abbott-freestyle-*Libre*) to access data from *LibreLinkUp* and then use Nightscout as a CGM.