add counter reset support

docs/fields-configuration.md

@@ -15,6 +15,15 @@ For each config entry the following fields are available:
 - `range` *optional (`date` type only)*: value will be generated between `from` and `to`. Only one between `from` and `to` can be set, in this case the dates will be generated between `from`/`to` and `time.Now()`. Progressive order of the generated dates is always assured regardless the interval involving `from`, `to` and `time.Now()` is positive or negative. If both at least one of `from` or `to` and `period` settings are defined an error will be returned and the generator will stop. The format of the date must be parsable by the following golang date format: `2006-01-02T15:04:05.999999999-07:00`. 
 - `cardinality` *optional*: exact number of different values to generate for the field; note that this setting may not be respected if not enough events are generated. For example, `cardinality: 1000` with `100` generated events would produce `100` different values, not `1000`. Similarly, the setting may not be respected if other settings prevents it. For example, `cardinality: 10` with an `enum` list of only 5 strings would produce `5` different values, not `10`. Or `cardinality: 10` for a `long` with `range.min: 1` and `range.max: 5` would produce `5` different values, not `10`. 
 - `counter` *optional (`long` and  `double` type only)*: if set to `true` values will be generated only ever-increasing. If `fuzziness` is not defined, the positive delta from the previous value will be totally random and unbounded. For example, assuming `counter: true`, assuming a `int` field type and with first value generated `10.`, will generate the second value with any random value greater than `10`, like `11` or `987615243`. If `fuzziness` is defined, the value will be generated within a positive delta defined by `fuzziness` from the previous value. For example, `fuzziness: 0.1`, assuming `counter: true` , assuming a `double` field type and with first value generated `10.`, will generate the second value in the range between `10.` and `11.`. Assuming the second value generated will be `10.5`, the third one will be generated in the range between `10.5` and `11.55`, and so on. If both `counter: true` and at least one of `range.min` or `range.max` settings are defined an error will be returned and the generator will stop.
+- `counter_reset` *optional (only applicable when `counter: true`)*: configures how and when the counter should reset. It has the following sub-fields:
+  - `strategy` *mandatory*: defines the reset strategy. Possible values are:
+      - `"random"`: resets the counter at random intervals.
+      - `"probabilistic"`: resets the counter based on a probability.
+      - `"after_n"`: resets the counter after a specific number each iteration.
+  - `probability` *required when strategy is "probabilistic"*: an integer between 1 and 100 representing the percentage chance of reset for each generated value.
+  - `reset_after_n` *required when strategy is "after_n"*: an integer specifying the number of values to generate before resetting the counter.
+
+Note: The `counter_reset` configuration is only applicable when `counter` is set to `true`. 
 - `period` *optional (`date` type only)*: values will be evenly generated between `time.Now()` and `time.Now().Add(period)`, where period is expressed as `time.Duration`. It accepts also a negative duration: in this case  values will be evenly generated between `time.Now().Add(period)` and `time.Now()`. If both `period` and at least one of `range.from` or `range.to` settings are defined an error will be returned and the generator will stop.
 - `object_keys` *optional (`object` type only)*: list of field names to generate in a object field type; if not specified a random number of field names will be generated in the object filed type
 - `value` *optional*: hardcoded value to set for the field (any `cardinality` will be ignored)