Added FAQ

FAQ.md

@@ -176,6 +176,7 @@ FairEmail follows all the best practices for an email client as decribed in [thi
 * [(104) What do I need to know about error reporting?](#user-content-faq104)
 * [(105) How does the roam-like-at-home option work?](#user-content-faq105)
 * [(106) Which launchers can show the number of new messages?](#user-content-faq106)
+* [(107) How do I used colored stars?](#user-content-faq107)
 
 [I have another question.](#support)
 
@@ -1734,6 +1735,21 @@ Note that this needs to be enabled in the advance options (default enabled).
 
 <br />
 
+<a name="faq107"></a>
+**(107) How do I use colored stars?**
+
+You can set a colored star via the *more* message menu, via multiple selection (started by long pressing a message)
+or automatically by using [rules](#user-content-faq71).
+
+You need to know that colored stars are not supported by the IMAP protocol and can therefore not be synchronized to an email server.
+This means that colored stars will not be visible in other email clients and will be lost on downloading messages again.
+However, the stars (without color) will be synchronized and will be visible in other email clients, when supported.
+
+Some email clients use IMAP keywords for colors.
+However, not all servers support IMAP keywords and besides that there are no standard keywords for colors.
+
+<br />
+
 ## Support
 
 If you have another question, want to request a feature or report a bug, you can use [this forum](https://forum.xda-developers.com/android/apps-games/source-email-t3824168).

README.md

@@ -36,7 +36,7 @@ This app starts a foreground service with a low priority status bar notification
 ## Pro features
 
 * Account/identity colors
-* Colored stars
+* Colored stars ([instructions](https://github.com/M66B/open-source-email/blob/master/FAQ.md#user-content-faq107))
 * Notifications per account (requires Android 8 Oreo or later)
 * Notification sound per sender (requires Android 8 Oreo or later)
 * Configurable notification actions