Update validation docs

Author: phpfui

docs/7. Validation.md

@@ -30,7 +30,7 @@ foreach ($validationErrors as $field => $fieldErrors)
 
 | Validator Name | Description | Parameters |
 | -------------- | ----------- | ----------- |
-| alnum  | Numbers and characters only (ctype_alnum) | None |
+| alpha_numeric | Numbers and characters only (ctype_alnum) | None |
 | alpha | Characters only (ctype_alpha) | None |
 | bool | Must be one or zero | None |
 | card | Credit card number (LUHN validation) | None |
@@ -56,10 +56,10 @@ foreach ($validationErrors as $field => $fieldErrors)
 | istarts_with | Field must start with (case insensitive) | comma separated list of strings |
 | lt_field | Less Than field | field, required |
 | lte_field | Less Than or Equal to field | field, required |
-| maxlength | Length must be greater or equal | Optional length, else MySQL limit |
-| maxvalue | Value must be greater or equal | value, required |
-| minlength | Must be less than or equal | number, default field size |
-| minvalue | Must be less than or equal | value, required |
+| maxlength | Length must be less than or equal | Optional length, else MySQL limit |
+| maxvalue | Value must be less than or equal | value, required |
+| minlength | Must be greater than or equal | number, default field size |
+| minvalue | Must be greater than or equal | value, required |
 | month_day_year | Loosely formatted date (M-D-Y) | None |
 | month_year | Loosely formatted Month Year | None |
 | neq_field | Not Equal to field | field, required |