Bug in tx_indexer config

[rootulp]

Context

I was trying to figure out the steps we should provide DevOps on how to disable the kv indexer and enable the lightweight transaction indexer.

Problem

On celestia-app v1.12.0, config.toml looks like this

# Options:
#   1) "null"
#   2) "kv" (default) - the simplest possible indexer, backed by key-value storage (defaults to levelDB; see DBBackend).
# 		- When "kv" is chosen "tx.height" and "tx.hash" will always be indexed.
#   3) "psql" - the indexer services backed by PostgreSQL.
# When "kv" or "psql" is chosen "tx.height" and "tx.hash" will always be indexed.
indexer = "null"

On celestia-app v1.13.0, config.toml looks like this:

# Options:
#   1) "kv"
#   2) "kv" (default) - the simplest possible indexer, backed by key-value storage (defaults to levelDB; see DBBackend).
# 		- When "kv" is chosen "tx.height" and "tx.hash" will always be indexed.
#   3) "psql" - the indexer services backed by PostgreSQL.
# When "kv" or "psql" is chosen "tx.height" and "tx.hash" will always be indexed.
indexer = "kv"

Acceptance Criteria

1. Fix the config so that there aren't two "kv" options. I think the first option should be "null".
2. [Tangent] Provide steps to DevOps on how to enable the lightweight tx indexer

cc: @ninabarbakadze

[cmwaters]

I think we should remove the (default) part (since we actually default to null)

[cmwaters]

Also I think this issue should be in celestia-core

[rootulp]

Moved to celestia-core. I propose we move the (default) part to null then. So the desired config would look like:

# Options:
#   1) "null" (default)
#   2) "kv" - the simplest possible indexer, backed by key-value storage (defaults to levelDB; see DBBackend).
# 		- When "kv" is chosen "tx.height" and "tx.hash" will always be indexed.
#   3) "psql" - the indexer services backed by PostgreSQL.
# When "kv" or "psql" is chosen "tx.height" and "tx.hash" will always be indexed.
indexer = "null"