docs: fix grammer for ledger docs #2743

Job	Run time
Basic Checks	3m 15s
Unit Tests	6m 34s
Integration Tests (raft)	11m 27s
Integration Tests (pvtdata)	13m 5s
Integration Tests (pvtdatapurge)	5m 21s
Integration Tests (ledger)	12m 58s
Integration Tests (lifecycle)	3m 56s
Integration Tests (e2e smartbft)	20m 10s
Integration Tests (discovery gossip devmode pluggable)	6m 54s
Integration Tests (gateway idemix pkcs11 configtx configtxlator)	17m 12s
Integration Tests (sbe nwo msp)	7m 0s
	1h 47m 52s

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