docs: misc. typos pt2

Remainder of typos found using `codespell -q 3 --skip="./shared,./src/systemd,*.po" -I ../NetworkManager-word-whitelist.txt` whereby whitelist consists of:
 ```
ans
busses
cace
cna
conexant
crasher
iff
liftime
creat
nd
sav
technik
uint
```

https://github.com/NetworkManager/NetworkManager/pull/205

docs/api/network-manager-docs.xml

@@ -258,7 +258,7 @@
     </chapter>
 
     <!--
-      These are obsolete and intentionally ommitted from the manual since they can't
+      These are obsolete and intentionally omitted from the manual since they can't
       appear on the D-Bus API of the present version of NetworkManager.
       Keep them here so that "make check" won't think that they were skipped accidentally .
       <xi:include href="dbus-org.freedesktop.NetworkManager.Device.WiMax.xml"/>

docs/libnm/libnm-docs.xml

@@ -69,7 +69,7 @@
         mapping D-Bus signals and properties to GObject signals and properties,
         and providing helpful accessor and utility functions.  However, unlike
         the old libnm-util/libnm-glib API, the mapping to the D-Bus API is not
-        exact, and various inconveniences and historical anomolies of the D-Bus
+        exact, and various inconveniences and historical anomalies of the D-Bus
         API are papered over.
       </para>
       <para>
@@ -295,7 +295,7 @@ print ("NetworkManager version " + client.get_version())]]></programlisting></in
   </chapter>
 
   <!--
-    These don't contain any useful documentaiton. Keep them here,
+    These don't contain any useful documentation. Keep them here,
     so that tools/check-docs.sh knows that we did omit them intentionally.
     <xi:include href="xml/nm-core-enum-types.xml"/>
     <xi:include href="xml/nm-enum-types.xml"/>