change {r} Sys.date() by !r Sys.date() in YAML header

Author: rikivillalba

vignettes/datatable-benchmarking.Rmd

@@ -1,6 +1,6 @@
 ---
 title: "Benchmarking data.table"
-date: "`{r} Sys.Date()`"
+date: !r Sys.Date()
 output:
   litedown::html_format:
     options:

vignettes/datatable-faq.Rmd

@@ -1,6 +1,6 @@
 ---
 title: "Frequently Asked Questions about data.table"
-date: "`{r} Sys.Date()`"
+date: !r Sys.Date()
 output:
   litedown::html_format:
     options:

vignettes/datatable-importing.Rmd

@@ -1,6 +1,6 @@
 ---
 title: "Importing data.table"
-date: "`{r} Sys.Date()`"
+date: !r Sys.Date()
 output:
   litedown::html_format
 vignette: >

vignettes/datatable-intro.Rmd

@@ -1,6 +1,6 @@
 ---
 title: "Introduction to data.table"
-date: "`{r} Sys.Date()`"
+date: !r Sys.Date()
 output:
   litedown::html_format
 vignette: >

vignettes/datatable-joins.Rmd

@@ -1,6 +1,6 @@
 ---
 title: "Joins in data.table"
-date: "`{r} Sys.Date()`"
+date: !r Sys.Date()
 output:
   litedown::html_format
 vignette: >

vignettes/datatable-keys-fast-subset.Rmd

@@ -1,6 +1,6 @@
 ---
 title: "Keys and fast binary search based subset"
-date: "`{r} Sys.Date()`"
+date: !r Sys.Date()
 output:
   litedown::html_format
 vignette: >

vignettes/datatable-programming.Rmd

@@ -1,6 +1,6 @@
 ---
 title: "Programming on data.table"
-date: "`{r} Sys.Date()`"
+date: !r Sys.Date()
 output:
   litedown::html_format
 vignette: >

vignettes/datatable-reference-semantics.Rmd

@@ -1,6 +1,6 @@
 ---
 title: "Reference semantics"
-date: "`{r} Sys.Date()`"
+date: !r Sys.Date()
 output:
   litedown::html_format
 vignette: >

vignettes/datatable-reshape.Rmd

@@ -1,6 +1,6 @@
 ---
 title: "Efficient reshaping using data.tables"
-date: "`{r} Sys.Date()`"
+date: !r Sys.Date()
 output:
   litedown::html_format
 vignette: >

vignettes/datatable-sd-usage.Rmd

@@ -1,6 +1,6 @@
 ---
 title: "Using .SD for Data Analysis"
-date: "`{r} Sys.Date()`"
+date: !r Sys.Date()
 output:
   litedown::html_format:
     options: