doc(bigtable): Fix misspelled words

[bhshkh]

Fixing below errors

$ ./bin/misspell .
admin.go:713:49: "colleciton" is a misspelling of "collection"
admin.go:1439:22: "minumum" is a misspelling of "minimum"
admin.go:1587:58: "deatils" is a misspelling of "details"
admin.go:2054:15: "teh" is a misspelling of "the"
bigtable_test.go:989:59: "reponse" is a misspelling of "response"
bigtable.go:1044:3: "Overriden" is a misspelling of "Overridden"
integration_test.go:2648:46: "alotted" is a misspelling of "allotted"
integration_test.go:2675:13: "Encyrption" is a misspelling of "Encryption"