_content/tour/static/js: fix type errors

script.js:694 TypeError: elm.draggable is not a function
    at http://127.0.0.1:3999/tour/script.js:10589:17
    at j (http://127.0.0.1:3999/tour/script.js:675:458)
    at e (http://127.0.0.1:3999/tour/script.js:671:248)
    at e (http://127.0.0.1:3999/tour/script.js:671:265)
    at j (http://127.0.0.1:3999/tour/script.js:675:398)
    at e (http://127.0.0.1:3999/tour/script.js:671:248)
    at http://127.0.0.1:3999/tour/script.js:670:312
    at k (http://127.0.0.1:3999/tour/script.js:782:156)
    at Object.$broadcast (http://127.0.0.1:3999/tour/script.js:722:240)
    at http://127.0.0.1:3999/tour/script.js:714:191 <div vertical-slide="" left="#left-side" right="#right-side">

_content/tour/static/partials/editor.html and _content/tour/static/css
use 'vertical-slide' and 'horizontal-slide'.
I don't know why go.dev does not report these errors.

Change-Id: I9e0f5bb2540af8e642281d7c350f57b69195624a
Reviewed-on: https://go-review.googlesource.com/c/website/+/527080
Run-TryBot: Hyang-Ah Hana Kim <hyangah@gmail.com>
Reviewed-by: Russ Cox <rsc@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
diff --git a/_content/tour/static/js/directives.js b/_content/tour/static/js/directives.js
index 76a1eb4..3f3083b 100755
--- a/_content/tour/static/js/directives.js
+++ b/_content/tour/static/js/directives.js
@@ -74,12 +74,12 @@
     }
 ]).
 
-// verticalSlide creates a sliding separator between the left and right elements.
+// vertical-slide creates a sliding separator between the left and right elements.
 // e.g.:
 // <div id="header">Some content</div>
 // <div vertical-slide top="#header" bottom="#footer"></div>
 // <div id="footer">Some footer</div>
-directive('verticalSlide', ['editor',
+directive('vertical-slide', ['editor',
     function(editor) {
         return function(scope, elm, attrs) {
             var moveTo = function(x) {
@@ -113,11 +113,11 @@
     }
 ]).
 
-// horizontalSlide creates a sliding separator between the top and bottom elements.
+// horizontal-slide creates a sliding separator between the top and bottom elements.
 // <div id="menu">Some menu</div>
 // <div vertical-slide left="#menu" bottom="#content"></div>
 // <div id="content">Some content</div>
-directive('horizontalSlide', ['editor',
+directive('horizontal-slide', ['editor',
     function(editor) {
         return function(scope, elm, attrs) {
             var moveTo = function(y) {