Update contribution guidelines + sort alphabetically

Author: thibmaek

.github/PULL_REQUEST_TEMPLATE.md

@@ -1,4 +1,5 @@
 # Please make sure all below checkboxes have been checked before submitting your PR.
+
 <!-- IMPORTANT:
   If you can check some boxes, please submit your PR first and then
   tick the boxes in the PR description. Don't place x'es in the square brackets [] directly.
@@ -8,10 +9,10 @@
 - [ ] I have read and understood the [contribution guidelines](https://github.com/thibmaek/awesome-raspberrypi/blob/master/CONTRIBUTING.md).
 - [ ] This pull request has a descriptive title. *(For example: `Add Raspbian`)*
 - The topic I added
-	- [ ] includes a valid (https) link,
-	- [ ] includes a concise and on-topic description,
-	- [ ] mentions if there is only support some devices,
-	- [ ] is not a duplicate,
-	- [ ] has been added at the bottom of the appropriate category,
-	- [ ] is in the form of **Named Link - Description, seperated by commas.**
-	- [ ] ends with a dot.
+  - [ ] includes a valid (https) link,
+  - [ ] includes a concise and on-topic description,
+  - [ ] mentions if there is only support some devices,
+  - [ ] is not a duplicate,
+  - [ ] has been in the correct alphabetical order for its section,
+  - [ ] is in the form of **Named Link - Description, seperated by commas.**
+  - [ ] ends with a dot.

CONTRIBUTING.md

@@ -6,7 +6,7 @@
 
 1. Make sure you are editing README.md only, no other files are allowed to be edited.
 2. Add your item to the category it belongs to. Try to avoid creating completely new categories.
-3. Make sure your item is added to the bottom of the items listed in a category, don't add it in at the middle.
+3. Make sure your item is added in the correct alphabetical order for its section.
 4. Don't submit dead links and try to always submit HTTPS links.
 5. Make sure you're linking to an English resource, other languages not allowed *at this moment*
 6. If there is only support for some devices please mention that by using the [badges](/media/badges) provided.