chars: add page (#3489)

pages/common/chars.md

@@ -0,0 +1,20 @@
+# chars
+
+> Display names and codes for various ASCII and Unicode characters and code points.
+> More information: <https://github.com/antifuchs/chars>.
+
+- Look up a character by its value:
+
+`chars '{{ß}}'`
+
+- Look up a character by its Unicode code point:
+
+`chars {{U+1F63C}}`
+
+- Look up possible characters given an ambiguous code point:
+
+`chars {{10}}`
+
+- Look up a control character:
+
+`chars "{{^C}}"`