Fix confusion with some changelogs

The changelogs that this commit will change are confusing. From a code
perspective, the rule Date was renamed to DateTime, and OneOf was
renamed to AnyOf, but because we also created a Date and OneOf rule with
different behaviours, it makes more sense to say that their behaviour
changed, rather than saying that they were created in version 2.0.0.

Signed-off-by: Henrique Moody <henriquemoody@gmail.com>

docs/rules/AnyOf.md

@@ -22,8 +22,7 @@ so `AnyOf()` returns true.
 
 Version | Description
 --------|-------------
-  2.0.0 | Renamed from `OneOf` to `AnyOf`
-  0.3.9 | Created
+  2.0.0 | Created
 
 ***
 See also:

docs/rules/Date.md

@@ -38,7 +38,8 @@ v::date('Ydm')->validate(20173112); // true
 
 Version | Description
 --------|-------------
-  2.0.0 | Created
+  2.0.0 | Changed to only validate dates
+  0.3.9 | Created as `Date`
 
 ***
 See also:

docs/rules/DateTime.md

@@ -41,8 +41,7 @@ Message template for this validator includes `{{format}}`.
 
 Version | Description
 --------|-------------
-  2.0.0 | Renamed from `Date` to `DateTime`
-  0.3.9 | Created as `Date`
+  2.0.0 | Created
 
 ***
 See also:

docs/rules/OneOf.md

@@ -23,7 +23,8 @@ character, one or the other, but not neither nor both.
 
 Version | Description
 --------|-------------
-  2.0.0 | Created (see [AnyOf](AnyOf.md))
+  2.0.0 | Changed to pass if only one inner validator passes
+  0.3.9 | Created
 
 ***
 See also: