Improve speed for entry page

[KUBOTA Shota]

before:

$ wrk -t2 -c40 -d30s http://localhost:3000/entry/using-atomic-design
Running 30s test @ http://localhost:3000/entry/using-atomic-design
  2 threads and 40 connections
  Thread Stats   Avg      Stdev     Max   +/- Stdev
    Latency   174.93ms   26.07ms 478.82ms   97.01%
    Req/Sec   115.49     27.32   190.00     69.81%
  6866 requests in 30.02s, 283.64MB read
Requests/sec:    228.73
Transfer/sec:      9.45MB

[KUBOTA Shota]

after:

$ wrk -t2 -c40 -d30s http://localhost:3000/entry/using-atomic-design
Running 30s test @ http://localhost:3000/entry/using-atomic-design
  2 threads and 40 connections
  Thread Stats   Avg      Stdev     Max   +/- Stdev
    Latency   172.33ms    7.50ms 271.77ms   88.59%
    Req/Sec   116.24     48.58   202.00     59.10%
  6949 requests in 30.02s, 287.07MB read
Requests/sec:    231.47
Transfer/sec:      9.56MB