Update mining.md

[jagottsicher]

minor changes to increase readability (easier copying) and a typo (echo needs double quotes if you want to add with >> append it to a file)

[coveralls]

Pull Request Test Coverage Report for Build 3963241340

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.01%) to 55.155%

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Totals
Change from base Build 3903303371:	0.01%
Covered Lines:	26562
Relevant Lines:	48159

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💛 - Coveralls

[jagottsicher]

put the quotes in again, commmited, and this pull request caught it.

[jcvernaleo]

Once the github actions finish running I'll merge.