Add information which is possible to cause conflict to doc

[LongTengDao]

I saw these ipc channels are used by @electron/remote in the source:

REMOTE_BROWSER_WRONG_CONTEXT_ERROR
REMOTE_BROWSER_REQUIRE
REMOTE_BROWSER_GET_BUILTIN
REMOTE_BROWSER_GET_GLOBAL
REMOTE_BROWSER_GET_CURRENT_WINDOW
REMOTE_BROWSER_GET_CURRENT_WEB_CONTENTS
REMOTE_BROWSER_CONSTRUCTOR
REMOTE_BROWSER_FUNCTION_CALL
REMOTE_BROWSER_MEMBER_CONSTRUCTOR
REMOTE_BROWSER_MEMBER_CALL
REMOTE_BROWSER_MEMBER_SET
REMOTE_BROWSER_MEMBER_GET
REMOTE_BROWSER_DEREFERENCE
REMOTE_BROWSER_CONTEXT_RELEASE

I'm not sure if here are other things like these, which is not written in doc, but could cause bugs that hard to happen and harder to debug.

Add things like these to doc is best. Then the userland won't think any ipc string is usable any more.

[linonetwo]

I think this conflict won't happen...who will use these strings?

[LongTengDao]

I think this is like the occupancy of global variables in daily programming, which cannot be ignored because of the low probability.