README: improve explanation of jinterface replacement

in your machine. If your installation of Erlang is not OTP 24, you should replace

the bundled `jinterface` library with the one from your Erlang installation.

Before running `make`, replace the package `com.ericsson.otp.erlang` from

`e-Knife/src` with the one from your Erlang distribution,

at `lib/jinterface-VERSION/java_src`.

Before running `make`, you must replace the package `com.ericsson.otp.erlang`

from `e-Knife/src/main/java` with the one that corresponds to your Erlang version.

You can either copy the files from your local installation (if available) or

download it from the OTP repository. After that, [rebuild the project](#build).

#### Copy jinterface from existing installation

Your Erlang distribution will most likely be installed at `/usr/lib/erlang`,

`/usr/local/lib/erlang`, `~/.local/lib/erlang` or `/usr/local/Cellar/erlang/VERSION/lib/erlang`.

Then, the library is located in `lib/jinterface-VERSION/java_src`

In some distributions (such as Ubuntu), you may need to install the `erlang-jinterface`

package.

As an example:

```bash

pkg="com/ericsson/otp/erlang"

rm -rf e-Knife/src/$pkg

mv /usr/lib/erlang/lib/jinterface-1.12/java_src/$pkg e-Knife/src/$pkg

erlang="/usr/lib/erlang"

rm -rf e-Knife/src/main/java/$pkg

mv $erlang/lib/jinterface-1.12/java_src/$pkg e-Knife/src/main/java/$pkg

```

#### Download jinterface from the repository

Check the version of OTP that you have installed by running the following snippet ([credit][so1]):

```bash

erl -eval '{ok, Version} = file:read_file(filename:join([code:root_dir(), "releases", erlang:system_info(otp_release), "OTP_VERSION"])), io:fwrite(Version), halt().' -noshell

```

Then, download the corresponding release:

```bash

VERSION=22.2.7

wget https://github.com/erlang/otp/archive/OTP-$VERSION.tar.gz

```

Finally, extract `lib/jinterface-$ver/java_src` to the corresponding location:

```bash

VERSION=22.2.7

pkg="com/ericsson/otp/erlang"

ji_path="lib/jinterface-1.10.1/java_src"

dest="e-Knife/src/main/java/$pkg"

rm -rf $dest

tar -xf OTP-$VERSION.tar.gz otp-OTP-$VERSION/$ji_path/$pkg

mv otp-OTP-$VERSION/$ji_path/$pkg $dest

rm -rf otp-OTP-$VERSION/

```

Finally, [rebuild the project](#build).

[credit]: https://stackoverflow.com/a/34326368

### UnsupportedClassVersionError: eknife/EKnife has been compiled by a more recent version of the Java Runtime