Use 16:9 aspect and bump reveal.js to 5.1.0

Change-Id: I6384639329daef18a40ca55cbd3c4eab0ae500e1
diff --git a/inst/reveal.js-5.1.0/css/theme/template/settings.scss b/inst/reveal.js-5.1.0/css/theme/template/settings.scss
new file mode 100644
index 0000000..3d54ac8
--- /dev/null
+++ b/inst/reveal.js-5.1.0/css/theme/template/settings.scss
@@ -0,0 +1,50 @@
+// Base settings for all themes that can optionally be
+// overridden by the super-theme
+
+// Background of the presentation
+$backgroundColor: #2b2b2b;
+
+// Primary/body text
+$mainFont: 'Lato', sans-serif;
+$mainFontSize: 40px;
+$mainColor: #eee;
+
+// Vertical spacing between blocks of text
+$blockMargin: 20px;
+
+// Headings
+$headingMargin: 0 0 $blockMargin 0;
+$headingFont: 'League Gothic', Impact, sans-serif;
+$headingColor: #eee;
+$headingLineHeight: 1.2;
+$headingLetterSpacing: normal;
+$headingTextTransform: uppercase;
+$headingTextShadow: none;
+$headingFontWeight: normal;
+$heading1TextShadow: $headingTextShadow;
+
+$heading1Size: 3.77em;
+$heading2Size: 2.11em;
+$heading3Size: 1.55em;
+$heading4Size: 1.00em;
+
+$codeFont: monospace;
+
+// Links and actions
+$linkColor: #13DAEC;
+$linkColorHover: lighten( $linkColor, 20% );
+
+// Text selection
+$selectionBackgroundColor: #FF5E99;
+$selectionColor: #fff;
+
+// Colors used for UI elements that are overlaid on top of
+// the presentation
+$overlayElementBgColor: 240, 240, 240;
+$overlayElementFgColor: 0, 0, 0;
+
+// Generates the presentation background, can be overridden
+// to return a background image or gradient
+@mixin bodyBackground() {
+	background: $backgroundColor;
+}