dev: use from_reader and to_writer_pretty from serde_json, remove reading from memory to string
#157
| Job | Run time |
|---|---|
| 30s | |
| 10s | |
| 1m 24s | |
| 1m 30s | |
| 2m 53s | |
| 5m 51s | |
| 4m 27s | |
| 16m 45s |