Bump version to 48.alpha

Update NEWS.

NEWS

@@ -1,3 +1,27 @@
+48.alpha
+========
+* classic: Add missing top-bar indicators [Florian; !339]
+* window-list: Fix window state styling [Florian; !342]
+* window-list: Fix "ignore-workspace" setting getting reset [Florian; !341]
+* window-list: Allow rearranging window buttons [Florian, Jakub; !338]
+* window-list: Add workspaces page to preference dialog [Florian; !344]
+* places-menu: Sync list of places with nautilus [Florian; !340]
+* places-menu: Fix a11y labelling [Florian; #542]
+* places-menu: Fix opening drives with mount operations [Florian; !361]
+* window-list: Fix hiding when entering overview with gestures [Florian; !364]
+* workspace-indicator: Only show previews of regular windows [Florian; !363]
+* window-list: Add attention indicator [Florian; !366]
+* Misc. bug fixes and cleanups [Florian, Bartłomiej; !337, !343, !345, !347,
+  !348, !349, !351, !352, !353, !354, !358, !362, !365, !367, !368, !370, !375]
+
+Contributors:
+  Florian Müllner, Bartłomiej Piotrowski, Jakub Steiner
+
+Translators:
+  Fabio Tomat [fur], Martin [sl], Jordi Mas i Hernandez [ca], Vasil Pupkin [be],
+  Nathan Follens [nl], Artur S0 [ru], Марко Костић [sr],
+  Yaron Shahrabani [he], Sabri Ünal [tr], Yi-Jyun Pan [zh_TW]
+
 47.0
 ====
 

meson.build

@@ -4,7 +4,7 @@
 
 project(
   'gnome-shell-extensions',
-  version: '47.0',
+  version: '48.alpha',
   meson_version: '>= 1.1.0',
   license: 'GPL-2.0-or-later',
 )