Description of feature

This issue is to collect all steps to implement pipeline level nf-tests to nf-core pipelines

• Add pipeline level nf-test documentation website#2536
• Add pipeline level nf-tests for template #2992
• Add nf-test to pipeline template CI workflow #2881
• Add linting for pipeline nf-tests (included in Add pipeline level nf-tests for template #2992)
• Add an option to opt-out nf-tests when creating a custom (non nf-core) pipeline
• Make sure that all references to old tests are updated (i.e. running pipeline tests with nextflow run) website#3380
• Lint for pipeline nf-test contents #3065
• Lint for tests/nextflow.config contents #3064
• Lint contents of nf-test.config #3063
• linting for nf-test snapshot #3049
• Adopt nf-test sharding #3243
• Tools pipeline tests use nf-test #3497 General: Update CI to test template pipelines with nf-test #3559