Tweaked syntax highlighting, added control flow to docs

I also found some issues in the code, so I fixed them first.

_getting_started/quick-start-guide.md

@@ -66,14 +66,53 @@ The usable types are as follows:
 
 ## Control Flow
 
-Watch this space.
+Performing different actions, or repeating an action multiple times, is essential for any general purpose language.
 
+Choosing between two options can be done with the `if-then-else` else statement. If the condition is 'truthy', the 'then-branch' will be executed. If the condition is not truthy, the optional 'else-branch' is executed instead.
+
+```toy
+var answer = 42;
+
+if (answer < 56) {
+    print "Success";
+}
+else {
+    print "Something's fishy here...";
+}
 ```
-if-then-else
-while
-for //not yet implemented
-continue
-break
+
+```toy
+var challenge = "hard";
+
+if (challenge == "hard") {
+    print "I choose to build a scripting language, not because it's easy, but because it's hard!";
+}
+
+//the else-branch is optional
+```
+
+To repeat a certain action, use the `while-then` loop, which repeats the body as long as the condition is true at the beginning of each loop.
+
+```toy
+var loops = 0;
+
+while (loops++ < 8) {
+    print "These episodes are endless.";
+}
+```
+
+To break out of a loop, you can use the `break` keyword. Alternatively, to restart the loop early, use the `continue` keyword.
+
+```toy
+var loops = 0;
+
+while (true) {
+    if (++loops < 15532) {
+        continue;
+    }
+
+    break; //poor yuki ;_;
+}
 ```
 
 ## Functions

_includes/styles/toylang-syntax.css

@@ -0,0 +1,7 @@
+/* copied from the main theme */
+pre:has(> code.language-toy) {
+    line-height: 1.18em;
+    overflow-x: auto;
+    width: fit-content;
+    max-width: 100%;
+}

_layouts/page.html

@@ -55,5 +55,6 @@ theme_url: https://github.com/pixeldroid/programming-pages
 {% include scripts/help.js %}
 
 {% comment %} provide user extension / override point {% endcomment %}
+{% include scripts/toylang-syntax.js %}
 {% include scripts/custom.js %}
 </script>