Update BridgeDB's Bridge Pool Assignments documentation

Looking over a recent bridge pool assignment file one can see:

005fd4d7decbb250055b861579e6fdc79ad17bee email transport=obfs4 ip=4 blocklist=ru
00782946f4c54ce1d028f21e541ef8440ecaa0ee settings ip=4 blocklist=ru
00a4295a8477453d6afe1ca4c2f19e3708e63fc4 email ip=4
00afd5ca2f89305b89171450cf34f247858f14e8 settings transport=obfs4 ip=4 blocklist=ru
00e1ae6cb75e47e363e6aef9f67a49c0e854fde7 moat transport=obfs4 ip=4
00e6f1d633d4e29db31f43d1e6e3e928e5c1810d moat transport=obfs4 ip=4 blocklist=ru
0110a6cf41a07637808fff79c0783ff37462b525 email ip=4 blocklist=ru
01292375ae04f41e7453d8e85df446c22a8d7101 settings ip=4 port=443 blocklist=ru
01341c9b4bc01b3a11e80a645a0bde45db02f04b moat transport=obfs4 ip=4
01436ef5b118fd95004a75f4616a6094d4aa4748 moat transport=obfs4 ip=4
0145c4524211a250519864627e4ae31eecccd39f moat transport=obfs4 ip=4
01520c1bb2c46bf0f54969b71217be04c1f8eb58 telegram transport=obfs4 ip=4 port=443

. However, our website does not know anything about settings or telegram or ip or blocklist or transport etc.