Memory quota exceeded on Heroku Dyno

**Steps to recreate:**
1. Upload large PDF file (Around 90 pages)

**Expected Result:**
1. Summaries displayed for each keyword

**Actual Result:**
1. Memory quota exceeded

Here's the Heroku log file:
```
2021-12-19T09:30:57.730982+00:00 heroku[web.1]: Process running mem=745M(145.7%)
2021-12-19T09:30:57.738828+00:00 heroku[web.1]: Error R14 (Memory quota exceeded)
2021-12-19T09:31:17.799640+00:00 heroku[web.1]: Process running mem=823M(160.8%)
2021-12-19T09:31:17.804447+00:00 heroku[web.1]: Error R14 (Memory quota exceeded)
2021-12-19T09:31:39.560621+00:00 heroku[web.1]: Process running mem=955M(186.6%)
2021-12-19T09:31:39.566113+00:00 heroku[web.1]: Error R14 (Memory quota exceeded)
2021-12-19T09:32:01.085454+00:00 heroku[web.1]: Process running mem=1133M(221.4%)
2021-12-19T09:32:01.089356+00:00 heroku[web.1]: Error R15 (Memory quota vastly exceeded)
2021-12-19T09:32:01.091093+00:00 heroku[web.1]: Stopping process with SIGKILL
2021-12-19T09:32:01.404680+00:00 heroku[web.1]: Process exited with status 137
2021-12-19T09:32:01.474608+00:00 heroku[web.1]: State changed from up to crashed
2021-12-19T09:32:01.479370+00:00 heroku[web.1]: State changed from crashed to starting
```