Merge pull request #6179 from cspannos/proposer-docs-syntax-error

Current syntax throws inaccurate error in op-proposer start script

docs/op-stack/src/docs/build/getting-started.md

@@ -522,12 +522,12 @@ Now start `op-proposer`, which proposes new state roots.
 cd ~/optimism/op-proposer
 
 ./bin/op-proposer \
-    --poll-interval 12s \
-    --rpc.port 8560 \
-    --rollup-rpc http://localhost:8547 \
-    --l2oo-address $L2OO_ADDR \
-    --private-key $PROPOSER_KEY \
-    --l1-eth-rpc $L1_RPC
+    --poll-interval=12s \
+    --rpc.port=8560 \
+    --rollup-rpc=http://localhost:8547 \
+    --l2oo-address=$L2OO_ADDR \
+    --private-key=$PROPOSER_KEY \
+    --l1-eth-rpc=$L1_RPC
 ```