Update usage-dictionary.mdx

Added information on how we use the ellipsis.

src/content/docs/style-guide/word-choice/usage-dictionary.mdx

@@ -391,6 +391,16 @@ Really, we recommend being as specific as possible to establish context. If a pi
     Instead of `e.g.`, use `for example` or `such as`. Subbing for `i.e.` is tricker, because sometimes people use it to mean `that is`, while at other times it's mis-used to mean `for example`. Read the context to be clear, but usually the best solution is to rewrite so the description is clear without needing explanatory text.
   </Collapser>
 
+  <Collapser
+    id="ellipses"
+    title="ellipses"
+  >
+    In quoted material, use an ellipsis to indicate omitted text. Treat an ellipsis as a unique character; that is, don’t use spaces between the three periods (this "..." but not this ". . ."). In the following example, “Security is important to us at New Relic.” is the complete sentence (so it ends with a period) and the missing next sentence is represented with an ellipsis. Note that a space precedes the ellipsis. Additionally, the beginning of the next sentence is preceded by a space.
+
+    “Security is important to us at New Relic. ... We hold ourselves to high standards, maintaining several certifications, including ISO 27001 and FedRAMP.”
+
+   </Collapser>
+
   <Collapser
     id="em-dash"
     title={<>em dash (<InlineCode>—</InlineCode>)</>}