Filtering: use a more thorough regex for zalgo & invisible chars

Install the regex package to take advantage of its support for Unicode
categories.

1 files changed, 1 insertions, 0 deletions

diff --git a/Pipfile b/Pipfile
index 7fab198f3..2ac5645dd 100644
--- a/Pipfile
+++ b/Pipfile
@@ -25,6 +25,7 @@ more_itertools = "~=8.2"
 python-dateutil = "~=2.8"
 python-frontmatter = "~=1.0.0"
 pyyaml = "~=5.1"
+regex = "==2021.4.4"
 requests = "~=2.22"
 sentry-sdk = "~=0.19"
 sphinx = "~=2.2"