Update escape filter reference summary

Added more context/ explanation for escape filter

Fixes issue in dev docs Shopify/shopify-dev#26494

lib/liquid/standardfilters.rb

@@ -73,7 +73,7 @@ def capitalize(input)
     # @liquid_type filter
     # @liquid_category string
     # @liquid_summary
-    #   Escapes a string.
+    #   Escapes special characters in HTML, such as `<>`, `'`, and `&`, and converts characters into escape sequences. The filter doesn't effect characters within the string that don’t have a corresponding escape sequence.".
     # @liquid_syntax string | escape
     # @liquid_return [string]
     def escape(input)