CLEVER 2.1 updates

[vilijajoyce]

Add in Department of Defense Opioid Use Disorder concepts and terms

• [x] https://github.com/suzytamang/clever-rockies/issues/41
• [x] https://github.com/suzytamang/clever-rockies/issues/43
• [x] https://github.com/suzytamang/clever-rockies/issues/45
• [x] https://github.com/suzytamang/clever-rockies/issues/47
• [x] https://github.com/suzytamang/clever-rockies/issues/49
• [x] https://github.com/suzytamang/clever-rockies/issues/51

Remove COVID concept and terms

• [x] https://github.com/suzytamang/clever-rockies/issues/53
• [x] https://github.com/suzytamang/clever-rockies/issues/55
• [x] https://github.com/suzytamang/clever-rockies/issues/57
• [x] https://github.com/suzytamang/clever-rockies/issues/59
• [x] https://github.com/suzytamang/clever-rockies/issues/61

Miscellaneous changes

• [x] https://github.com/suzytamang/clever-rockies/issues/64
• [x] https://github.com/suzytamang/clever-rockies/issues/66
• [ ] Update CLEVER_steps.ipynb file to reflect new output directory
• [ ] Update step2.sh to reflect new CORPUS input and new output
• [ ] Update step3.sh to reflect new METADATA input and new output
• [ ] Update step5.sh to reflect new output