docs: add ERRATA section to the datasheet

document the undefined pin states issue

docs/ERRATA.md

@@ -0,0 +1,7 @@
+# Chip Errata
+
+This section lists the known issues with the chip and suggests workarounds where possible.
+
+## Undefined pin states
+
+The state of the bidirectional pins and output pins is not defined when no design is selected. This means that the bidirectional pins may be configured as outputs, with either high or low output values, or as inputs. Take care to avoid shorting the bidirectional pins to other outputs or to VDD or GND when no design is selected. As a workaround, you can connect these pins to external devices or other pins through a resistor.

documentation.py

@@ -66,6 +66,9 @@ class Docs():
         doc_header = self.load_doc_template('doc_header.md')
         doc_template = self.load_doc_template('doc_template.md')
         doc_info = self.load_doc_template("../../tt-multiplexer/docs/INFO.md")
+        doc_errata = self.load_doc_template('ERRATA.md')
+        doc_errata = self.load_doc_template("../../tt-multiplexer/docs/INFO.md")
+        doc_errata = self.load_doc_template('ERRATA.md')
         doc_credits = self.load_doc_template('CREDITS.md')
 
         with open(self.args.dump_markdown, 'w') as fh:
@@ -116,6 +119,8 @@ class Docs():
             # ending
             fh.write(doc_info)
             fh.write("\n\clearpage\n")
+            fh.write(doc_errata)
+            fh.write("\n\clearpage\n")
             fh.write(doc_credits)
 
         logging.info(f'wrote markdown to {self.args.dump_markdown}')