download: Reword Edge channel description (MR 157)

Make it clear that something will break sooner or later and it's meant
primarily for development.

content/page/download.md

@@ -7,7 +7,7 @@ title: "Download"
 <small>[#latest release#] Download Links</small>
 
 [#grid text#]
-### [#latest release#]
+### [#latest release#] (stable)
 Official postmarketOS images are available for devices in the *main* and
 *community* categories. All of them are run a
 [(close to) mainline](https://wiki.postmarketos.org/wiki/(Close_to)_Mainline)
@@ -18,8 +18,13 @@ be fixed (e.g. SMS not working). Refer to the
 
 [#latest release#] is recommended for best stability.
 
-### Edge (Rolling Release)
-Development happens in edge, the rolling release channel of postmarketOS.
+### Edge (unstable)
+Edge is the development channel for postmarketOS and, as a result,
+experiences [frequent issues that affect stability](/edge/). Some of these
+issues may even prevent a device from booting completely.
+
+It is *not* recommended to run Edge if a stable experience is desired.
+
 Find downloads for devices in *main* and *community* categories
 [here](https://images.postmarketos.org/bpo/edge/). To install postmarketOS to
 one of the many
@@ -28,9 +33,6 @@ or to customize your installation otherwise (e.g. install another user
 interface), use *pmbootstrap* as explained in the
 [installation guide](https://wiki.postmarketos.org/wiki/Installation_guide).
 
-Edge is recommended for development (latest features,
-[occasional breakage](/edge/)).
-
 [#grid end#]
 
 ## Notes