docs: fixed a typo: ngx.now returns time of the resolution of milliseonds, rather than microseconds. thanks Wang Xi.

README

@@ -2874,7 +2874,7 @@ Nginx API for Lua
     header_filter_by_lua*, log_by_lua**
 
     Returns a floating-point number for the elapsed time in seconds
-    (including microseconds as the decimal part) from the epoch for the
+    (including milliseconds as the decimal part) from the epoch for the
     current time stamp from the nginx cached time (no syscall involved
     unlike Lua's date library).
 

README.markdown

@@ -2728,7 +2728,7 @@ ngx.now
 
 **context:** *set_by_lua*, rewrite_by_lua*, access_by_lua*, content_by_lua*, header_filter_by_lua*, log_by_lua**
 
-Returns a floating-point number for the elapsed time in seconds (including microseconds as the decimal part) from the epoch for the current time stamp from the nginx cached time (no syscall involved unlike Lua's date library).
+Returns a floating-point number for the elapsed time in seconds (including milliseconds as the decimal part) from the epoch for the current time stamp from the nginx cached time (no syscall involved unlike Lua's date library).
 
 Use the Nginx core [timer_resolution](http://wiki.nginx.org/CoreModule#timer_resolution) directive to adjust the accuracy or forcibly update the Nginx time cache by calling [ngx.update_time](http://wiki.nginx.org/HttpLuaModule#ngx.update_time) first.
 

doc/HttpLuaModule.wiki

@@ -2636,7 +2636,7 @@ Updates of the Nginx time cache an be forced by calling [[#ngx.update_time|ngx.u
 
 '''context:''' ''set_by_lua*, rewrite_by_lua*, access_by_lua*, content_by_lua*, header_filter_by_lua*, log_by_lua*''
 
-Returns a floating-point number for the elapsed time in seconds (including microseconds as the decimal part) from the epoch for the current time stamp from the nginx cached time (no syscall involved unlike Lua's date library).
+Returns a floating-point number for the elapsed time in seconds (including milliseconds as the decimal part) from the epoch for the current time stamp from the nginx cached time (no syscall involved unlike Lua's date library).
 
 Use the Nginx core [[CoreModule#timer_resolution|timer_resolution]] directive to adjust the accuracy or forcibly update the Nginx time cache by calling [[#ngx.update_time|ngx.update_time]] first.