Fixed README.md

#### Setting up the config

Before usage, **config.yml** needs to be set up:

- ltr paths - executable, prosite and tRNAdb

- ltr arguments 

- gt sketch path

- gt sketch arguments

- blastx protein database (our database available at ... )

- ltr finder paths - executable, prosite and tRNAdb

- ltr finder arguments 

- genome tools sketch path

- genome tools sketch arguments

- blastx protein database (installed together with TE-greedy-nester)

- blastx arguments

**Note**: `config.yml` is located by default in directory `/etc/nested/.`