docs: update XML Schema for nfdc status after the recent changes

Plus some minor docs updates

Change-Id: Ieb8d6f520c47c022087354d745e33fff58c2d875
diff --git a/docs/schema.rst b/docs/schema.rst
index f4c7611..4006afd 100644
--- a/docs/schema.rst
+++ b/docs/schema.rst
@@ -4,9 +4,9 @@
 =====================
 
 The NFD status XML schema describes the structure of the NFD status XML
-document generated by command ``nfd-status``.
+document generated by the command ``nfdc status report xml``.
 
-Users can use this schema to validate the generated XML document.
+This schema can be used to validate the generated XML document.
 
 .. literalinclude:: _static/nfd-status.xsd
    :language: xml