[docs] Add Christopher as maintainer

CONTRIBUTING.md

@@ -33,8 +33,9 @@ CI tests in order to be merged.
 
 ## When in doubt, ask
 
-The dedicated maintainers of modm are [@salkinium](https://github.com/salkinium)
-and [@rleh](https://github.com/rleh) and you can always ping them.
+The dedicated maintainers of modm are [@salkinium](https://github.com/salkinium),
+[@rleh](https://github.com/rleh) and [@chris-durand](https://github.com/chris-durand).
+You can always ping them.
 
 If you want to add a new platform, or other significant functionality, we
 [ask you to discuss that in a thread first][ideas]. We are very open to

README.md

@@ -742,15 +742,15 @@ See [CONTRIBUTING.md][contrib] for our contribution guidelines.
 
 <!--authors-->
 The modm project is maintained by
-Niklas Hauser ([\@salkinium](https://github.com/salkinium)) and
-Raphael Lehmann ([\@rleh](https://github.com/rleh)) with significant contributions from
+Niklas Hauser ([\@salkinium](https://github.com/salkinium)),
+Raphael Lehmann ([\@rleh](https://github.com/rleh)) and
+Christopher Durand ([\@chris-durand](https://github.com/chris-durand)) with significant contributions from
 Sascha Schade ([\@strongly-typed](https://github.com/strongly-typed)),
 Fabian Greif ([\@dergraaf](https://github.com/dergraaf)),
 Kevin Läufer ([\@ekiwi](https://github.com/ekiwi)),
 Martin Rosekeit ([\@thundernail](https://github.com/thundernail)),
 Daniel Krebs ([\@daniel-k](https://github.com/daniel-k)),
 Georgi Grinshpun ([\@georgi-g](https://github.com/georgi-g)),
-Christopher Durand ([\@chris-durand](https://github.com/chris-durand))
 David Hebbeker ([\@dhebbeker](https://github.com/dhebbeker)),
 Thorsten Lajewski ([\@TheTh0r](https://github.com/TheTh0r)),
 Mike Wolfram ([\@mikewolfram](https://github.com/mikewolfram))