Update contribution guidelines to ink! 3.0 (#527)

* [chores] Fix typo

* [chores] Update list of topics

* [chores] ink ➜ ink!

* [chores] Update Riot channel link

CONTRIBUTING.md

-# Contributing to ink
+# Contributing to ink!
 
 First of all, thank you for taking your time to contribute to ink!
 
-> [I don't want to contribute, I just have some questions! :S](#I-dont-want-to-contrubute-I-just-have-some-questions)
+> [I don't want to contribute, I just have some questions! :S](#I-dont-want-to-contribute-I-just-have-some-questions)
 
 ## Code of Conduct
 
@@ -17,13 +17,16 @@ Please follow our simple commit style guidelines.
 
 1. Prepend all commits with a topic.
    Available topics are:
-    - `[core]` For changes to `ink_core`
-    - `[model]` For changes to `ink_model`
-    - `[lang]` For changes to `ink_lang`
-    - `[cli]` For changes to `cargo-pdsl` also known as `pdsl_cli`
+    - `[storage]` For changes to `ink_storage`.
+    - `[env]` For changes to `ink_env`.
+    - `[lang]` For changes to `ink_lang`.
+    - `[allocator]` For changes to `ink_allocator`.
+    - `[metadata]` For changes to `ink_metadata`.
+    - `[prelude]` For changes to `ink_prelude`.
+    - `[primitives]` For changes to `ink_primitives`.
     - `[ci]` For changes to the continuous integration.
     - `[chores]` For general non-technical changes.
-    - `[examples/{core,model,lang}]` For changes to the examples in either `core`, `model` or `lang`.
+    - `[examples]` For changes to the examples.
 
 For other purposes and sections please try to find a good fit for the topic.
 
@@ -46,7 +49,7 @@ Following these will ensure that your pull request is going to be accepted.
 1. We won't accept a pull request with `FIXME` or `TODO` comments in it.
    Please try to fix them by yourself and resolve all remaining to-do items.
    If that is not possible then write an issue for each of them and link to the source line and commit with a proper description. For more information go [here](#Issues-&-pull-requests).
-1. Document everything properly that you have written, refactored or touched. Especially keeping documentation up-to-date is very important. For larger portions please try to also update the ink wiki or write a new entry there.
+1. Document everything properly that you have written, refactored or touched. Especially keeping documentation up-to-date is very important. For larger portions please try to also update the ink! wiki or write a new entry there.
 1. Write tests for your code. If your code is hard to test, try to find a design that allows for testability.
 1. If needed also update the [`README`](README.md).
 1. For performance critical parts we also want additional performance tests.
@@ -81,7 +84,7 @@ You want to write an issue if you have a
 - bug report
 - technical question
 
-about the ink.
+about the ink! project.
 
 > Please use GitHub's search functionality to see if the question has already been asked,
 the feature has already been proposed or the bug has already been reported.
@@ -98,10 +101,10 @@ A pull request should be doing or implementing exactly one semantic issue. So fo
 
 For a nice list of hints visit this [link][GitHub Perfect Pull Reqest].
 
-## I don't want to contrubute I just have some questions
+## I don't want to contribute, I just have some questions
 
-For questions about the ink project, about Parity Technologies or general technical related questions you are welcome to contact us via [Riot][Riot-Substrate-Technical]. For technical questions specifically about the ink and its sub-projects you may also file an issue. For more information about filing issues go [here](#Issues-&-pull-requests).
+For questions about the ink! project, about Parity Technologies or general technical related questions you are welcome to contact us via [Riot][Riot-Smart-Contracts-ink]. For technical questions specifically about the ink! and its sub-projects you may also file an issue. For more information about filing issues go [here](#Issues-&-pull-requests).
 
-[Riot-Substrate-Technical]: https://riot.im/app/#/room/#substrate-technical:matrix.org
+[Riot-Smart-Contracts-ink]: https://riot.im/app/#/room/!tYUCYdSvSYPMjWNDDD:matrix.parity.io
 
 [GitHub Perfect Pull Reqest]: https://github.blog/2015-01-21-how-to-write-the-perfect-pull-request/