[doc] Use consistent spelling/capitalization of names

Consistently use the following spelling for document formats,
programming languages, and names:

- Markdown
- Hjson
- JSON
- Verilog
- HTML
- GitHub
- CSS
- Python

Also avoid abbreviations:
- repo -> repository

Signed-off-by: Philipp Wagner <phw@lowrisc.org>
diff --git a/util/container/Dockerfile b/util/container/Dockerfile
index 7472813..eabee52 100644
--- a/util/container/Dockerfile
+++ b/util/container/Dockerfile
@@ -83,7 +83,7 @@
     srecord \
     zlib1g-dev
 
-# Install Python3 and support libraries. Cleanup install in place to reduce
+# Install Python 3 and support libraries. Cleanup install in place to reduce
 # binary size.
 RUN apt-get install -y \
     python3 \
@@ -91,7 +91,7 @@
     python3-setuptools && \
     apt-get clean; rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/* /usr/share/doc/*
 
-# Copy repo into tmp directory to execute additional install steps.
+# Copy repository into tmp directory to execute additional install steps.
 COPY python-requirements.txt /tmp/python-requirements.txt
 RUN pip3 install -r /tmp/python-requirements.txt