Updating DESCRIPTION in response to CRAN request

DESCRIPTION

@@ -2,14 +2,15 @@ Package: gFormulaMI
 Title: G-Formula for Causal Inference via Multiple Imputation
 Version: 1.0.0
 Authors@R: 
-    c(person("Jonathan", "Bartlett", , "jonathan.bartlett1@lshtm.ac.uk", role = c("aut", "cre"),
+    c(person("Jonathan", "Bartlett", email = "jonathan.bartlett1@lshtm.ac.uk", role = c("aut", "cre"),
            comment = c(ORCID = "0000-0001-7117-0195")),
            person("Camila", "Olarte Parra", email = "camila.olarte-parra@lshtm.ac.uk", role = "ctb",
            comment = c(ORCID = "0000-0003-0263-4392")),
            person("Erik", "van Zwet", email = "e.w.van_zwet@lumc.nl", role = "ctb"))
 Description: Implements the G-Formula method for causal inference with time-varying treatments and
-  confounders using Bayesian multiple imputation methods. It creates multiple synthetic imputed
-  datasets under treatment regimes of interest using the mice package. These can then be analysed
+  confounders using Bayesian multiple imputation methods, as described by
+  Bartlett, Olarte Parra and Daniel (2023) <arXiv:2301.12026>. It creates multiple synthetic imputed
+  datasets under treatment regimes of interest using the 'mice' package. These can then be analysed
   using rules developed for analysing multiple synthetic datasets.
 License: GPL (>= 3)
 Encoding: UTF-8