Fix MD026 warnings

The following warnings are generated by using markdownlint analysis:
```
docs/Network-Configuration.md:58:25 MD026/no-trailing-punctuation Trailing punctuation in heading [Punctuation: ':']
```
Refer to markdown-lint [1] to fix MD026
[1]: https://github.com/updownpress/markdown-lint/blob/master/rules/026-no-trailing-punctuation.md

Signed-off-by: George Liu <liuxiwei@ieisystem.com>
Change-Id: I0ceefdccaee128bce0d86228bda819a9482074e2
1 file changed