Fix apidocs error for /api/v3/challenges/group/:groupId. Change various descriptions to imperative mood

e.g., change "Sets lastCron" to "Set lastCron"

website/server/controllers/api-v3/challenges.js

@@ -111,7 +111,7 @@ api.createChallenge = {
 };
 
 /**
- * @api {post} /api/v3/challenges/:challengeId/join Joins a challenge
+ * @api {post} /api/v3/challenges/:challengeId/join Join a challenge
  * @apiVersion 3.0.0
  * @apiName JoinChallenge
  * @apiGroup Challenge
@@ -158,7 +158,7 @@ api.joinChallenge = {
 };
 
 /**
- * @api {post} /api/v3/challenges/:challengeId/leave Leaves a challenge
+ * @api {post} /api/v3/challenges/:challengeId/leave Leave a challenge
  * @apiVersion 3.0.0
  * @apiName LeaveChallenge
  * @apiGroup Challenge
@@ -241,7 +241,7 @@ api.getUserChallenges = {
 };
 
 /**
- * @api {get} /api/v3/challenges/group/group:Id Get challenges for a group
+ * @api {get} /api/v3/challenges/group/:groupId Get challenges for a group
  * @apiDescription Get challenges that the user is a member, public challenges and the ones from the user's groups.
  * @apiVersion 3.0.0
  * @apiName GetGroupChallenges

website/server/controllers/api-v3/debug.js

@@ -55,7 +55,7 @@ api.addHourglass = {
 };
 
 /**
- * @api {post} /api/v3/debug/set-cron Sets lastCron for user
+ * @api {post} /api/v3/debug/set-cron Set lastCron for user
  * @apiDescription Only available in development mode.
  * @apiVersion 3.0.0
  * @apiName setCron

website/server/controllers/api-v3/quests.js

@@ -301,7 +301,7 @@ api.forceStart = {
 };
 
 /**
- * @api {post} /api/v3/groups/:groupId/quests/cancel Cancels a quest that is not active
+ * @api {post} /api/v3/groups/:groupId/quests/cancel Cancel a quest that is not active
  * @apiVersion 3.0.0
  * @apiName CancelQuest
  * @apiGroup Group
@@ -403,7 +403,7 @@ api.abortQuest = {
 };
 
 /**
- * @api {post} /api/v3/groups/:groupId/quests/leave Leaves the active quest
+ * @api {post} /api/v3/groups/:groupId/quests/leave Leave the active quest
  * @apiVersion 3.0.0
  * @apiName LeaveQuest
  * @apiGroup Group

website/server/controllers/api-v3/user.js

@@ -859,7 +859,7 @@ api.userPurchaseHourglass = {
 };
 
 /**
-* @api {post} /api/v3/user/read-card/:cardType Reads a card
+* @api {post} /api/v3/user/read-card/:cardType Read a card
 * @apiVersion 3.0.0
 * @apiName UserReadCard
 * @apiGroup User
@@ -1329,7 +1329,7 @@ api.userReset = {
 };
 
 /**
-* @api {post} /api/v3/user/custom-day-start Sets preferences.dayStart for user
+* @api {post} /api/v3/user/custom-day-start Set preferences.dayStart for user
 * @apiVersion 3.0.0
 * @apiName setCustomDayStart
 * @apiGroup User