- remove a word from the string datatype description for clarity

- time-interval values are the number of seconds

doc/ZConfig/zconfig.tex

@@ -860,14 +860,14 @@ The following data types are provided by the default type registry.
 \term{\datatype{string}}
   Returns the input value as a string.  If the source is a Unicode
   string, this implies that it will be checked to be simple 7-bit
-  \ASCII.  This is the default data type for key values in
+  \ASCII.  This is the default data type for values in
   configuration files.
 
 \term{\datatype{time-interval}}
-  A specification of a time interval, with multiplier suffixes (for
-  example, \code{12h}).  Suffixes are case insensitive and may be
-  \samp{s} (seconds), \samp{m} (minutes), \samp{h} (hours), or
-  \samp{d} (days).
+  A specification of a time interval in seconds, with multiplier
+  suffixes (for example, \code{12h}).  Suffixes are case insensitive
+  and may be \samp{s} (seconds), \samp{m} (minutes), \samp{h} (hours),
+  or \samp{d} (days).
 
 \end{definitions}