Fix MD026 warnings

The following warnings are generated by using markdownlint analysis:
```
MD026/no-trailing-punctuation Trailing punctuation in heading [Punctuation: ':']
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: I1b6aa54e010140a2a6c42b7f900611a204df587a
diff --git a/README.md b/README.md
index 070be6e..9c53680 100644
--- a/README.md
+++ b/README.md
@@ -1,13 +1,13 @@
 # phosphor-host-ipmid
 
-## Compile ipmid with default options:
+## Compile ipmid with default options
 
 ```ascii
 meson builddir
 ninja -C builddir
 ```
 
-## Compile ipmid with yocto defaults:
+## Compile ipmid with yocto defaults
 
 ```ascii
 meson builddir -Dbuildtype=minsize -Db_lto=true -Dtests=disabled
@@ -32,7 +32,7 @@
 ninja -C builddir
 ```
 
-## Generate test coverage report:
+## Generate test coverage report
 
 ```ascii
 meson builddir -Db_coverage=true -Dtests=enabled
diff --git a/docs/oem-extension-numbering.md b/docs/oem-extension-numbering.md
index cdbb112..9afa33a 100644
--- a/docs/oem-extension-numbering.md
+++ b/docs/oem-extension-numbering.md
@@ -10,7 +10,7 @@
 - For each such code, describe the associated messages, including
   representation, function, meaning, limits, and so on.
 
-### OEM Extensions, Block Transfer Transport Example.
+### OEM Extensions, Block Transfer Transport Example
 
 This table and the next briefly recap OEM Extension messages as described in the
 [IPMI Specification](http://www.intel.com/content/www/us/en/servers/ipmi/ipmi-second-gen-interface-spec-v2-rev1-1.html).