ruby-mode.el: Expand some docstrings with examples

* lisp/progmodes/ruby-mode.el (ruby-align-chained-calls)
(ruby-method-params-indent): Expand docstrings with examples.

lisp/progmodes/ruby-mode.el

@@ -336,7 +336,15 @@ Only has effect when `ruby-use-smie' is t."
   "If non-nil, align chained method calls.
 
 Each method call on a separate line will be aligned to the column
-of its parent.
+of its parent. Example:
+
+  my_array.select { |str| str.size > 5 }
+          .map    { |str| str.downcase }
+
+When nil, each method call is indented with the usual offset:
+
+  my_array.select { |str| str.size > 5 }
+    .map    { |str| str.downcase }
 
 Only has effect when `ruby-use-smie' is t."
   :type 'boolean
@@ -346,12 +354,26 @@ Only has effect when `ruby-use-smie' is t."
 (defcustom ruby-method-params-indent t
   "Indentation  of multiline method parameters.
 
-When t, the parameters list is indented to the method name.
+When t, the parameters list is indented to the method name:
+
+  def foo(
+        baz,
+        bar
+      )
+    hello
+  end
 
 When a number, indent the parameters list this many columns
 against the beginning of the method (the \"def\" keyword).
 
-The value nil means the same as 0.
+The value nil means the same as 0:
+
+  def foo(
+    baz,
+    bar
+  )
+    hello
+  end
 
 Only has effect when `ruby-use-smie' is t."
   :type '(choice (const :tag "Indent to the method name" t)