Fix wording in process overview documentation (#393)

1. Fix wording in process overview documentation
2. Add header to separate the priority 1 & 2 table for better readability

Signed-off-by: Chidananda Swamy R <chidananda.swamy@ltts.com>

Author: Chidananda-Swamy

docs/internals/requirements/process_overview.rst

@@ -10,10 +10,13 @@ how well this tool implements process requirements.
 Unsatisfied Process Requirements
 ################################
 
-The following table lists tool requirements from our process
+The following table lists process requirements from our process
 which are not (yet) satisfied,
 i.e. covered by tool requirements.
 
+Unsatisfied – Priority 1
+------------------------
+
 .. needtable::
    :types: gd_req
    :columns: id;title;tags
@@ -51,6 +54,9 @@ i.e. covered by tool requirements.
           continue
        results.append(need)
 
+Unsatisfied – Priority 2
+------------------------
+
 .. needtable::
    :types: gd_req
    :columns: id;title;tags