update docs for ngx_http_sysguard_module

English and Chinese version.

Updated for sysguard_rt and sysguard_mode directives.

Signed-off-by: Paul Yang(InfoHunter) <paulyang.inf@gmail.com>
add docs for ngx_http_upstream_dynamic_module

English and Chinese versions.

Signed-off-by: Paul Yang(InfoHunter) <paulyang.inf@gmail.com>
Fix doc error of http_upstream_dynamic

Signed-off-by: Paul Yang(InfoHunter) <paulyang.inf@gmail.com>
Merge pull request #82 from InfoHunter/master

update docs for sysguard module and add docs for upstream dynamic module