Function parse

parse(content: string): { rate: number; unit: string; description: string }
Parser for ratelimit tags - defines MQTT rate limiting recommendations

This parser handles the ratelimit tag that defines recommended rate limits for MQTT publishing or subscribing. It extracts:
- Rate value (number)
- Time unit (second, minute, hour, day)
- Optional description
Parameters
- content: string
  Raw content from the ratelimit tag
Returns { rate: number; unit: string; description: string }
Parsed rate limit information, or null if parsing fails
Example: Messages per second
```
// Input: "10/second Maximum telemetry frequency"
// Output: { rate: 10, unit: "second", description: "Maximum telemetry frequency" }
```
Example: Commands per minute
```
// Input: "5/minute Command rate limit per device"
// Output: { rate: 5, unit: "minute", description: "Command rate limit per device" }
```
Example: Simple rate limit
```
// Input: "100/hour"
// Output: { rate: 100, unit: "hour", description: "" }
```
Since
4.1.0

Public
- Defined in core/parsers/mqtt_ratelimit.ts:34