[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/hw/ip/rv_timer/util/reg_timer.py b/hw/ip/rv_timer/util/reg_timer.py
index c9ab05c..4209060 100755
--- a/hw/ip/rv_timer/util/reg_timer.py
+++ b/hw/ip/rv_timer/util/reg_timer.py
@@ -2,7 +2,7 @@
 # Copyright lowRISC contributors.
 # Licensed under the Apache License, Version 2.0, see LICENSE for details.
 # SPDX-License-Identifier: Apache-2.0
-r"""Mako template to hjson register description
+r"""Mako template to Hjson register description
 """
 import sys
 import argparse