full review post-trial 04 and tutorials-middle

[avallecam]

This PR aims to collect edit suggestions from trial 04 and the tutorials-middle repository.

This includes any specific addition to:

• add content on epidemiological background or field applications
• add conceptual explanations of methods

All rendered content is in https://epiverse-trace.github.io/tutorials-middle/

[github-actions]

⚠️ WARNING ⚠️

This pull request contains a mix of workflow files and regular files. This could be malicious. No preview will be created.

regular files:

• .lintr
• CODE_OF_CONDUCT.md
• CONTRIBUTING.md
• LICENSE.md
• README.Rmd
• README.md
• config.yaml
• episodes/create-forecast.Rmd
• episodes/create-forecast_files/figure-html/unnamed-chunk-4-1.png
• episodes/create-forecast_files/figure-html/unnamed-chunk-8-1.png
• episodes/data/ebola_cases.csv
• episodes/data/sarscov2_cases_deaths.csv
• episodes/data/set-01-contacts.rds
• episodes/data/set-01-linelist.rds
• episodes/data/set-02-contacts.rds
• episodes/data/set-02-linelist.rds
• episodes/data/set-03-contacts.rds
• episodes/data/set-03-linelist.rds
• episodes/data/set-04-contacts.rds
• episodes/data/set-04-linelist.rds
• episodes/data/set-05-contacts.rds
• episodes/data/set-05-linelist.rds
• episodes/data/set-06-contacts.rds
• episodes/data/set-06-linelist.rds
• episodes/fig/SEE-dist.png
• episodes/fig/SEE-individual-reproductive-number-fig-b.png
• episodes/fig/SEE-individual-reproductive-number-fig-c-d.png

workflow files:

• .github/workflows/README.md
• .github/workflows/lint.yaml
• .github/workflows/sandpaper-version.txt

[avallecam]

no feedback was provided. closing to move on with the pending issues in isolated PRs