Fix typos/grammer in contributing

CONTRIBUTING.md

@@ -8,15 +8,15 @@
 
 ## I want to contribute artwork or documentation
 
-Some issues that need artwork and documentation to be resolved are tagged [`non technical`](https://github.com/lichess-org/lila/issues?q=is%3Aissue+is%3Aopen+label%3A%22non+technical%22).
+Some issues that need artwork and documentation to be resolved are tagged [`nontechnical`](https://github.com/lichess-org/lila/issues?q=is%3Aissue+is%3Aopen+label%3A%22non+technical%22).
 
 ## I want to report a bug or a problem about Lichess
 
 [**Make an issue**](https://github.com/lichess-org/lila/issues/new). Before creating an issue, make sure that:
 
 1. You list the steps to reproduce the problem to show that other users may experience it as well, if the issue is not self-descriptive.
 2. Search to make sure it isn't a duplicate. [The advanced search syntax](https://help.github.com/articles/searching-issues/) may come in handy.
-3. It is not a trivial problem or demand unrealistic dev time to fix. Such issues may be closed.
+3. It is not a trivial problem or demands unrealistic dev time to fix. Such issues may be closed.
 
 Report mobile-only bugs to [Lichess mobile](https://github.com/lichess-org/lichobile).
 
@@ -25,11 +25,11 @@ Report mobile-only bugs to [Lichess mobile](https://github.com/lichess-org/licho
 Issue tickets on features that lack potential or effectiveness are not useful and may be closed. Discussions regarding whether a proposed new feature would be useful can be done on the [Lichess Feedback Forum](https://lichess.org/forum/lichess-feedback) to gauge feedback. The developers may also discuss the idea there, and if it is exemplary, a corresponding issue ticket will be made. **When you're ready, [make an issue ticket](https://github.com/lichess-org/lila/issues/new)** and link relevant, constructive comments regarding it in your issue ticket (such as a detailed Reddit post; linking to an empty forum thread with only your own commentary adds no value). Make sure that the feature you propose:
 
 1. Is **effective in delivering a goal**. A feature that adds nothing new is purely fancy; please develop a userscript or userstyle for your personal use instead.
-2. Doesn't rely on mundane assumptions. Non-technical people have the tendency to measure how difficult / easy a feature is to implement based on their unreliable instincts, and such assumptions wastes everyone's time. **Point out what needs to happen**, not what you think will happen.
+2. Doesn't rely on mundane assumptions. Non-technical people have the tendency to measure how difficult / easy a feature is to implement based on their unreliable instincts, and such assumptions waste everyone's time. **Point out what needs to happen**, not what you think will happen.
 3. Is **unique, if you're aiming to solve a problem**. Features that can easily be replaced by easier ideas have little value and may not have to be brought up to begin with.
 4. Is **clear and concise**. If ambiguities exist, define them or propose options.
 
-## I want to help translating Lichess
+## I want to help translate Lichess
 
 Check out [Lichess on crowdin.com](https://crowdin.com/project/lichess).