add frog_date to metadata

Author: exaexa

refs.bib

@@ -111,6 +111,14 @@ @manual{rfc3629
   url={https://www.rfc-editor.org/info/rfc3629}
 }
 
+@manual{iso8601,
+  title={Date and time: Representations for information interchange -- Part 1: Basic rules},
+  series={ISO},
+  number={8601-1},
+  year={2019},
+  url={https://www.iso.org/iso-8601-date-and-time-format.html}
+}
+
 @article{orth2010reconstruction,
   title={Reconstruction and use of microbial metabolic networks: the core Escherichia coli metabolic model as an educational guide},
   author={Orth, Jeffrey D and Fleming, Ronan MT and Palsson, Bernhard {\O}},

text/spec.tex

@@ -147,6 +147,10 @@ \subsection{Metadata file}
  & optional
  & identifier of the FROG report that is unique within a given data repository
  \\
+\verb|frog_date|
+ & optional
+ & date of creating the FROG report, preferably in ISO-8601~\cite{iso8601} format, for example \texttt{2023-02-23}
+ \\
 \verb|model_filename|
  & required
  & expected base name of the model file, such as \verb|e_coli_core.xml|