[SPARK-18264][SPARKR] build vignettes with package, update vignettes for CRAN release build and add info on release

## What changes were proposed in this pull request?

Changes to DESCRIPTION to build vignettes.
Changes the metadata for vignettes to generate the recommended format (which is about <10% of size before). Unfortunately it does not look as nice
(before - left, after - right)

![image](https://cloud.githubusercontent.com/assets/8969467/20040492/b75883e6-a40d-11e6-9534-25cdd5d59a8b.png)

![image](https://cloud.githubusercontent.com/assets/8969467/20040490/a40f4d42-a40d-11e6-8c91-af00ddcbdad9.png)

Also add information on how to run build/release to CRAN later.

## How was this patch tested?

manually, unit tests

shivaram

We need this for branch-2.1

Author: Felix Cheung <felixcheung_m@hotmail.com>

Closes #15790 from felixcheung/rpkgvignettes.

1 files changed, 91 insertions, 0 deletions

diff --git a/R/CRAN_RELEASE.md b/R/CRAN_RELEASE.md
new file mode 100644
index 0000000000..bea8f9fbe4
--- /dev/null
+++ b/R/CRAN_RELEASE.md
@@ -0,0 +1,91 @@
+# SparkR CRAN Release
+
+To release SparkR as a package to CRAN, we would use the `devtools` package. Please work with the
+`dev@spark.apache.org` community and R package maintainer on this.
+
+### Release
+
+First, check that the `Version:` field in the `pkg/DESCRIPTION` file is updated. Also, check for stale files not under source control.
+
+Note that while `check-cran.sh` is running `R CMD check`, it is doing so with `--no-manual --no-vignettes`, which skips a few vignettes or PDF checks - therefore it will be preferred to run `R CMD check` on the source package built manually before uploading a release.
+
+To upload a release, we would need to update the `cran-comments.md`. This should generally contain the results from running the `check-cran.sh` script along with comments on status of all `WARNING` (should not be any) or `NOTE`. As a part of `check-cran.sh` and the release process, the vignettes is build - make sure `SPARK_HOME` is set and Spark jars are accessible.
+
+Once everything is in place, run in R under the `SPARK_HOME/R` directory:
+
+```R
+paths <- .libPaths(); .libPaths(c("lib", paths)); Sys.setenv(SPARK_HOME=tools::file_path_as_absolute("..")); devtools::release(); .libPaths(paths)
+```
+
+For more information please refer to http://r-pkgs.had.co.nz/release.html#release-check
+
+### Testing: build package manually
+
+To build package manually such as to inspect the resulting `.tar.gz` file content, we would also use the `devtools` package.
+
+Source package is what get released to CRAN. CRAN would then build platform-specific binary packages from the source package.
+
+#### Build source package
+
+To build source package locally without releasing to CRAN, run in R under the `SPARK_HOME/R` directory:
+
+```R
+paths <- .libPaths(); .libPaths(c("lib", paths)); Sys.setenv(SPARK_HOME=tools::file_path_as_absolute("..")); devtools::build("pkg"); .libPaths(paths)
+```
+
+(http://r-pkgs.had.co.nz/vignettes.html#vignette-workflow-2)
+
+Similarly, the source package is also created by `check-cran.sh` with `R CMD build pkg`.
+
+For example, this should be the content of the source package:
+
+```sh
+DESCRIPTION	R		inst		tests
+NAMESPACE	build		man		vignettes
+
+inst/doc/
+sparkr-vignettes.html
+sparkr-vignettes.Rmd
+sparkr-vignettes.Rman
+
+build/
+vignette.rds
+
+man/
+ *.Rd files...
+
+vignettes/
+sparkr-vignettes.Rmd
+```
+
+#### Test source package
+
+To install, run this:
+
+```sh
+R CMD INSTALL SparkR_2.1.0.tar.gz
+```
+
+With "2.1.0" replaced with the version of SparkR.
+
+This command installs SparkR to the default libPaths. Once that is done, you should be able to start R and run:
+
+```R
+library(SparkR)
+vignette("sparkr-vignettes", package="SparkR")
+```
+
+#### Build binary package
+
+To build binary package locally, run in R under the `SPARK_HOME/R` directory:
+
+```R
+paths <- .libPaths(); .libPaths(c("lib", paths)); Sys.setenv(SPARK_HOME=tools::file_path_as_absolute("..")); devtools::build("pkg", binary = TRUE); .libPaths(paths)
+```
+
+For example, this should be the content of the binary package:
+
+```sh
+DESCRIPTION	Meta		R		html		tests
+INDEX		NAMESPACE	help		profile		worker
+```