Doc: Online style: Decrease font size of enum tables' Value column

A table in enum doc may have long literal strings defined
as enum values - they take up space from the Description column,
and often force a scrollbar to appear, making the entire
table difficult to read.

Alleviate this by reducing the font size for the text in Value
column.

Change-Id: I18495a4f506851f9eff2cd94f5cdfcb03096c698
Task-number: QTWEBSITE-658
Reviewed-by: Martin Smith <martin.smith@theqtcompany.com>
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@theqtcompany.com>

doc/global/template/style/online.css

@@ -1261,6 +1261,9 @@ table td,table th {
 table.alignedsummary,table.propsummary {
   width:initial
 }
+table.valuelist td.tblval {
+  font-size:0.75em
+}
 div.main_index .row {
   border-bottom:1px solid #eee
 }