feat(ubuntu20-04): added build files for ugrep

ubuntu20-04/build-ugrep.dockerfile

@@ -0,0 +1,21 @@
+# step 1: create a container for ugrep named "ugrep"
+# docker -D build --no-cache -t ugrep .
+#
+# step 2: run bash in the container, e.g. to run ugrep from the command line
+# docker run -it ugrep bash
+#
+# step 3: run ugrep in the container, for example:
+# ugrep -r -n -tjava Hello ugrep/tests/
+
+FROM ubuntu:20.04
+
+WORKDIR /build/ugrep
+
+RUN apt-get update \
+    && apt-get install -y make vim git clang wget unzip libpcre2-dev libz-dev libbz2-dev liblzma-dev liblz4-dev libzstd-dev
+
+RUN git clone https://github.com/Genivia/ugrep /build/ugrep
+
+RUN ./build.sh
+
+CMD ["sleep", "infinity"]