README.md cargo build command misses a flag

[mvds00]

Describe the bug

Building subtensor leads to a non-functioning binary (with fatal errors such as "runtime requires function imports which are not present on the host: 'env:ext_benchmarking_current_time_version_1'") which is solved by adding --features=runtime-benchmarks as mentioned in the Discord. It would be nice if the README would reflect this requirement.

To Reproduce

1. Go to https://github.com/opentensor/subtensor
2. Follow the build instructions, especially cargo build --release
3. Run the subtensor
4. Observe it crashing with error "runtime requires function imports which are not present on the host: 'env:ext_benchmarking_current_time_version_1'"

Expected behavior

I expect a working binary after performing the build instructions.

Screenshots

No response

Environment

Linux Ubuntu

Additional context

It seems to be solved by adding --features=runtime-benchmarks to the cargo build command.