doc: Document the NBFT API

Added an explicit note about unstable API, that is in fact
semi-unstable whereas existing structures are stable and
new API will possibly be added at the end of the structs.

Signed-off-by: Tomas Bzatek <[email protected]>

Author: tbzatek

doc/api.rst.in

@@ -16,3 +16,4 @@ functions.
 .. include::   rst/filters.rst
 .. include::   rst/util.rst
 .. include::   rst/log.rst
+.. include::   rst/nbft.rst

src/nvme/nbft.h

@@ -12,6 +12,14 @@
 #include <sys/types.h>
 #include "util.h"
 
+/**
+ * DOC: nbft.h
+ *
+ * NVM Express Boot Specification, Revision 1.0
+ *
+ * Note: this API is currently unstable, subject to further additions.
+ */
+
 /*
  *  ACPI NBFT table structures (TP8012 Boot Specification rev. 1.0)
  */