feat: install yq directly from alpine without extra repo

Signed-off-by: Khosrow Moossavi <khos2ow@gmail.com>

Author: khos2ow

Dockerfile

@@ -14,9 +14,6 @@
 
 FROM quay.io/terraform-docs/terraform-docs:edge
 
-# this is explicitly needed because yq v4.x only exists in this repo.
-RUN echo "http://dl-4.alpinelinux.org/alpine/edge/community" >> /etc/apk/repositories
-
 RUN set -x \
     && apk update \
     && apk add --no-cache \