Update activities.md I changed line 4 "organiZation" to match the rest of the...

Update activities.md I changed line 4 "organiZation" to match the rest of the document. to "organiSation" even though US English prefers the Z version. The documentation now is consistent throughout this page.

On lines 24, 105 and forward I capitalized "Activity Types" to be consistent with the title Creating new Activity Types. also 107, 112, 123, and 144

On lines 6, 11, 17, 19, 23, 28, 31, 32, 33, 34, 36, 38, 42, 44, 46, 53, 71, 125, 132, and 134 capitalized Activity or Activities. This was made to keep the consistency of using Activity, Activities and Types used after Activity.