[css-overscroll-1] Remove redundant colon

Author: lahmatiy

css-overscroll-1/Overview.bs

@@ -175,7 +175,7 @@ Applies to: <a>scroll container</a> elements
 Inherited: no
 Media: visual
 Computed value: see individual properties
-Animation type:: discrete
+Animation type: discrete
 Canonical order: <abbr title="follows order of property value definition">per grammar</abbr>
 </pre>
 
@@ -223,7 +223,7 @@ Inherited: no
 Percentages: N/A
 Media: visual
 Computed value: as specified
-Animation type:: discrete
+Animation type: discrete
 Canonical order: <abbr title="follows order of property value definition">per grammar</abbr>
 </pre>
 
@@ -246,7 +246,7 @@ Inherited: no
 Percentages: N/A
 Media: visual
 Computed value: as specified
-Animation type:: discrete
+Animation type: discrete
 Canonical order: <abbr title="follows order of property value definition">per grammar</abbr>
 </pre>