doc: add @shigeki and @mscdex to TC
doc: add @shigeki and @mscdex to TC

voted in to Node.js Foundation TSC in meeting on 2015-06-17

Closes: https://github.com/nodejs/io.js/issues/1500
Closes: https://github.com/nodejs/io.js/issues/1501
PR-URL: https://github.com/nodejs/io.js/pull/2008
Reviewed-By: Ben Noordhuis <59bd0a3ff43b32849b319e645d4798d8a5d1e889@bnoordhuis.nl>

dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node