Update documentation and changelog for infiniteSky

Author: NicksWorld

docs/changelog.txt

@@ -52,6 +52,7 @@ Template for new versions:
 # Future
 
 ## New Tools
+- `infiniteSky`: (reinstated) tool for automatically creating new z-levels of sky
 
 ## New Features
 - `tweak`: ``realistic-melting``: change melting return for inorganic armor parts, shields, weapons, trap components and tools to stop smelters from creating metal, bring melt return for adamantine in line with other metals to ~95% of forging cost. wear reduces melt return by 10% per level

docs/plugins/infiniteSky.rst

@@ -2,8 +2,8 @@ infiniteSky
 ===========
 
 .. dfhack-tool::
-    :summary: Automatically allocate new z-levels of sky
-    :tags: unavailable
+    :summary: Automatically allocate new z-levels of sky.
+    :tags: fort auto design map
 
 If enabled, this plugin will automatically allocate new z-levels of sky at the
 top of the map as you build up. Or it can allocate one or many additional levels