Add instructions to build docker image locally

Makefile

@@ -7,7 +7,7 @@ BUILD_DATE := $(shell date -u +%FT%TZ)
 ETLHASH=stellar/stellar-etl:$(shell git rev-parse --short HEAD)
 
 docker-build:
-	$(SUDO) docker build --pull --no-cache --label org.opencontainers.image.created="$(BUILD_DATE)" \
+	$(SUDO) docker build --platform linux/amd64 --pull --no-cache --label org.opencontainers.image.created="$(BUILD_DATE)" \
 	-t $(ETLHASH) -t stellar/stellar-etl:latest -f ./docker/Dockerfile .
 
 docker-push:

README.md

@@ -55,7 +55,19 @@ If branch is already made, just rename it _before passing the pull request_.
 
 1. Clone this repo `git clone https://github.com/stellar/stellar-etl`
 2. Build stellar-etl with `go build`
-3. Run export commands to export information about the legder
+3. Build the docker image locally with `make docker-build`
+4. Run the docker container in interactive mode to run export commands.
+
+```sh
+$ docker run --platform linux/amd64 -it stellar/stellar-etl:latest /bin/bash
+```
+
+5. Run export commands to export information about the legder
+   Example command to export ledger data
+
+```sh
+root@71890b878fca:/etl/data# stellar-etl export_ledgers --start-ledger 1000 --end-ledger 500000 --output exported_ledgers.txt
+```
 
 > _*Note:*_ If using the GCS datastore, you can run the following to set GCP credentials to use in your shell
 
@@ -65,6 +77,12 @@ gcloud config set project dev-hubble
 gcloud auth application-default login
 ```
 
+Add following to docker run command to pass gcloud credentials to docker container
+
+```
+-e GOOGLE_APPLICATION_CREDENTIALS=/.config/gcp/credentials.json -v "$HOME/.config/gcloud/application_default_credentials.json":/.config/gcp/credentials.json:ro
+```
+
 > _*Note:*_ Instructions for installing gcloud can be found [here](https://cloud.google.com/sdk/docs/install-sdk)
 
 <br>

internal/utils/main.go

@@ -235,7 +235,7 @@ func AddCommonFlags(flags *pflag.FlagSet) {
 	flags.Bool("futurenet", false, "If set, will connect to Futurenet instead of Mainnet.")
 	flags.StringToStringP("extra-fields", "u", map[string]string{}, "Additional fields to append to output jsons. Used for appending metadata")
 	flags.Bool("captive-core", false, "If set, run captive core to retrieve data. Otherwise use TxMeta file datastore.")
-	flags.String("datastore-path", "sdf-ledger-close-metas/ledgers", "Datastore bucket path to read txmeta files from.")
+	flags.String("datastore-path", "sdf-ledger-close-meta/ledgers", "Datastore bucket path to read txmeta files from.")
 	flags.Uint32("buffer-size", 200, "Buffer size sets the max limit for the number of txmeta files that can be held in memory.")
 	flags.Uint32("num-workers", 10, "Number of workers to spawn that read txmeta files from the datastore.")
 	flags.Uint32("retry-limit", 3, "Datastore GetLedger retry limit.")