Add explanations to scrape-examples integration test

Author: willcrichton

src/test/rustdoc-gui/scrape-examples-button-focus.goml renamed to src/test/rustdoc-gui/scrape-examples-interactions.goml

@@ -1,5 +1,6 @@
 goto: "file://" + |DOC_PATH| + "/scrape_examples/fn.test.html"
 
+// The next/prev buttons vertically scroll the code viewport between examples
 store-property: (initialScrollTop, ".scraped-example-list > .scraped-example pre", "scrollTop")
 focus: ".scraped-example-list > .scraped-example .next"
 press-key: "Enter"
@@ -12,6 +13,7 @@ assert-property: (".scraped-example-list > .scraped-example pre", {
 	"scrollTop": |initialScrollTop|
 })
 
+// The expand button increases the scrollHeight of the minimized code viewport
 store-property: (smallOffsetHeight, ".scraped-example-list > .scraped-example pre", "offsetHeight")
 assert-property-false: (".scraped-example-list > .scraped-example pre", {
 	"scrollHeight": |smallOffsetHeight|
@@ -26,11 +28,15 @@ assert-property: (".scraped-example-list > .scraped-example pre", {
 	"scrollHeight": |fullOffsetHeight|
 })
 
+// Clicking "More examples..." will open additional examples
 assert-attribute-false: (".more-examples-toggle", {"open": ""})
 click: ".more-examples-toggle"
 assert-attribute: (".more-examples-toggle", {"open": ""})
+
+// Toggling all docs will close additional examples
 click: "#toggle-all-docs"
 assert-attribute-false: (".more-examples-toggle", {"open": ""})
+
 // After re-opening the docs, the additional examples should stay closed
 click: "#toggle-all-docs"
 assert-attribute-false: (".more-examples-toggle", {"open": ""})