fix introduced `:` ; fix another typo

guides/source/active_support_instrumentation.md

@@ -465,7 +465,7 @@ Creating custom events
 Adding your own events is easy as well. `ActiveSupport::Notifications` will take care of
 all the heavy lifting for you. Simply call `instrument` with a `name`, `payload` and a block.
 The notification will be sent after the block returns. `ActiveSupport` will generate the start and end times
-as well as the unique ID. All data passed into the `insturment` call will make it into the payload.
+as well as the unique ID. All data passed into the `instrument` call will make it into the payload.
 
 Here's an example:
 

guides/source/form_helpers.md

@@ -423,7 +423,7 @@ Whenever Rails sees that the internal value of an option being generated matches
 
 TIP: The second argument to `options_for_select` must be exactly equal to the desired internal value. In particular if the value is the integer 2 you cannot pass "2" to `options_for_select` — you must pass 2. Be aware of values extracted from the `params` hash as they are all strings.
 
-WARNING: when `:include_blank` or `:prompt:` are not present, `:include_blank` is forced true if the select attribute `required` is true, display `size` is one and `multiple` is not true.
+WARNING: when `:include_blank` or `:prompt` are not present, `:include_blank` is forced true if the select attribute `required` is true, display `size` is one and `multiple` is not true.
 
 You can add arbitrary attributes to the options using hashes: