Fix some typos (#9)

Author: timokau

source/creating-github-app.rst

@@ -61,7 +61,7 @@ More reading: https://developer.github.com/apps/building-github-apps/authenticat
 
 How exactly can we create the ``installation access token`` from an ``installation_id``?
 The documentation linked above has more details, but the process is as follows.
-We will be creating a JWT (JSON web token with the GitHub App's ID, and GitHub
+We will be creating a JWT (JSON web token) with the GitHub App's ID, and GitHub
 App's Private Key. We will then pass in the JWT and ``installation_id`` to GitHub,
 and GitHub will provide us with an ``installation_access_token``.
 

source/responding-to-webhook.rst

@@ -114,12 +114,12 @@ Notice that the repository name is provided in the webhook, under the list of
 "repositories". So we can iterate on it and construct the url as follows::
 
     for repository in event.data['repositories']:
-        url = f"/repos/{repository['full_name'}/issues"
+        url = f"/repos/{repository['full_name']}/issues"
 
 
 The next piece we want to figure out is what should the comment message be. For
 this exercise, we want to thank the author, and say something like
-"Thanks for installing me, @author!".get(
+"Thanks for installing me, @author!".
 
 Take a look again at the issue event payload::