[SPARK-18514][DOCS] Fix the markdown for `Note:`/`NOTE:`/`Note that` across R API documentation

## What changes were proposed in this pull request?

It seems in R, there are

- `Note:`
- `NOTE:`
- `Note that`

This PR proposes to fix those to `Note:` to be consistent.

**Before**

![2016-11-21 11 30 07](https://cloud.githubusercontent.com/assets/6477701/20468848/2f27b0fa-afde-11e6-89e3-993701269dbe.png)

**After**

![2016-11-21 11 29 44](https://cloud.githubusercontent.com/assets/6477701/20468851/39469664-afde-11e6-9929-ad80be7fc405.png)

## How was this patch tested?

The notes were found via

```bash
grep -r "NOTE: " .
grep -r "Note that " .
```

And then fixed one by one comparing with API documentation.

After that, manually tested via `sh create-docs.sh` under `./R`.

Author: hyukjinkwon <gurwls223@gmail.com>

Closes #15952 from HyukjinKwon/SPARK-18514.

2 files changed, 8 insertions, 5 deletions

diff --git a/R/pkg/R/DataFrame.R b/R/pkg/R/DataFrame.R
index 4e3d97bb3a..9a51d530f1 100644
--- a/R/pkg/R/DataFrame.R
+++ b/R/pkg/R/DataFrame.R
@@ -2541,7 +2541,8 @@ generateAliasesForIntersectedCols <- function (x, intersectedColNames, suffix) {
 #'
 #' Return a new SparkDataFrame containing the union of rows in this SparkDataFrame
 #' and another SparkDataFrame. This is equivalent to \code{UNION ALL} in SQL.
-#' Note that this does not remove duplicate rows across the two SparkDataFrames.
+#'
+#' Note: This does not remove duplicate rows across the two SparkDataFrames.
 #'
 #' @param x A SparkDataFrame
 #' @param y A SparkDataFrame
@@ -2584,7 +2585,8 @@ setMethod("unionAll",
 #' Union two or more SparkDataFrames
 #'
 #' Union two or more SparkDataFrames. This is equivalent to \code{UNION ALL} in SQL.
-#' Note that this does not remove duplicate rows across the two SparkDataFrames.
+#'
+#' Note: This does not remove duplicate rows across the two SparkDataFrames.
 #'
 #' @param x a SparkDataFrame.
 #' @param ... additional SparkDataFrame(s).
diff --git a/R/pkg/R/functions.R b/R/pkg/R/functions.R
index f8a9d3ce5d..bf5c96373c 100644
--- a/R/pkg/R/functions.R
+++ b/R/pkg/R/functions.R
@@ -2296,7 +2296,7 @@ setMethod("n", signature(x = "Column"),
 #' A pattern could be for instance \preformatted{dd.MM.yyyy} and could return a string like '18.03.1993'. All
 #' pattern letters of \code{java.text.SimpleDateFormat} can be used.
 #'
-#' NOTE: Use when ever possible specialized functions like \code{year}. These benefit from a
+#' Note: Use when ever possible specialized functions like \code{year}. These benefit from a
 #' specialized implementation.
 #'
 #' @param y Column to compute on.
@@ -2341,7 +2341,7 @@ setMethod("from_utc_timestamp", signature(y = "Column", x = "character"),
 #' Locate the position of the first occurrence of substr column in the given string.
 #' Returns null if either of the arguments are null.
 #'
-#' NOTE: The position is not zero based, but 1 based index. Returns 0 if substr
+#' Note: The position is not zero based, but 1 based index. Returns 0 if substr
 #' could not be found in str.
 #'
 #' @param y column to check
@@ -2779,7 +2779,8 @@ setMethod("window", signature(x = "Column"),
 #' locate
 #'
 #' Locate the position of the first occurrence of substr.
-#' NOTE: The position is not zero based, but 1 based index. Returns 0 if substr
+#'
+#' Note: The position is not zero based, but 1 based index. Returns 0 if substr
 #' could not be found in str.
 #'
 #' @param substr a character string to be matched.