Add documentation.

website/docs/os.getSystemTags.md

@@ -0,0 +1,17 @@
+Returns the list of tags corresponding to a system.
+
+There are tags specific to each operating system, and meta tags like `posix`, `darwin`, `desktop` and `mobile` tags.
+
+### Examples ###
+```lua
+print("iOS system tags: " .. os.getSystemTags("ios"))
+-- { "ios", "darwin", "posix", "mobile" },
+```
+
+### See Also ###
+[os.istarget](os.istarget.md)
+
+### Availability ###
+
+Premake 5.0.0 beta 3 or later.
+

website/docs/os.istarget.md

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+Checks the target operating system against a particular identifier or tag.
+See [os.getSystemTags](os.getSystemTags.md) for documentation about OS tags.
+
+### Examples ###
+```lua
+print("Android: " .. os.istarget("android"))
+print("Mobile: " .. os.istarget("mobile"))
+print("Desktop: " .. os.istarget("posix"))
+```
+
+### See Also ###
+[os.getSystemTags](os.getSystemTags.md)
+
+### Availability ###
+
+Premake 5.0.0 beta 3 or later.
+

website/sidebars.js

@@ -385,13 +385,15 @@ module.exports = {
 						'os.getcwd',
 						'os.getnumcpus',
 						'os.getpass',
+						'os.getSystemTags',
 						'os.getversion',
 						'os.host',
 						'os.is',
 						'os.is64bit',
 						'os.isdir',
 						'os.isfile',
 						'os.islink',
+						'os.istarget',
 						'os.locate',
 						'os.matchdirs',
 						'os.matchfiles',