Fix Prawn docs link (#36)

* Fix Prawn docs link

* Update README.md

Co-authored-by: Chris Oliver <excid3@gmail.com>

---------

Co-authored-by: Chris Oliver <excid3@gmail.com>

README.md

@@ -151,7 +151,7 @@ If not set, it will fall back to Prawn's default behavior.
 
 `details` and `line_items` allow inline formatting with Prawn. This allows you to use HTML tags to format text: `<b>` `<i>` `<u>` `<strikethrough>` `<sub>` `<sup>` `<font>` `<color>` `<link>`
 
-See [the Prawn docs](https://prawnpdf.org/api-docs/2.3.0/Prawn/Text.html#text-instance_method) for more information.
+See [the Prawn docs](https://prawnpdf.org/) for more information.
 
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