Improvements to RNAseq and Genomics courses (#875)

**RNAseq course improvements**

- Added workflow outputs and test profiles in nextflow.config instead of inline defaults.
- Improved solution file structure (previously per-section, now per-part with modules)
- Improved scaffold files: rnaseq.nf and 4 module stubs for learners to fill in.
- New SVG diagrams: 4 Excalidraw workflow/method diagrams.
- Supporting files: Updated index.md, next_steps.md, survey.md, 00_orientation.md.

**Genomics course improvements**

- Expanded methodology lesson with improved wording, output display, and directory contents admonitions.
- Improved scaffold files
- Improved solution scripts
- Replaced sample_bams.txt with samplesheet.csv from the get-go

**Cross-course consistency work**

- Standardized workflow dev lesson opening structure: Assignment, Lesson plan, consistent working directory tips etc.
- Consistent figure placement in Assignment sections.
- Links to Part 1 method overview with section anchors.
- More consistent wording and structure throughout

Author: vdauwera

docs/en/docs/nf4_science/genomics/00_orientation.md

@@ -73,36 +73,35 @@ tree . -L 2
     ├── data
     │   ├── bam
     │   ├── ref
-    │   ├── sample_bams.txt
     │   └── samplesheet.csv
     ├── genomics.nf
     ├── modules
     │   ├── gatk_haplotypecaller.nf
+    │   ├── gatk_jointgenotyping.nf
     │   └── samtools_index.nf
     ├── nextflow.config
     └── solutions
-        ├── modules
-        ├── nf-test.config
         ├── part2
-        └── tests
+        └── part3
 
-    8 directories, 8 files
+    7 directories, 6 files
     ```
 
 Click on the colored box to expand the section and view its contents.
 We use collapsible sections like this to display expected command output as well as directory and file contents in a concise way.
 
-- **The `genomics.nf` file** is a workflow script that you'll build up over the course.
+- **The `genomics.nf` file** is a scaffold for a workflow script that you'll build up as you go through the course.
 
-- **The `modules` directory** contains skeleton module files that you'll fill in during the course.
+- **The `modules` directory** contains scaffolds for process module that you'll fill in during the course.
 
 - **The file `nextflow.config`** is a configuration file that sets minimal environment properties.
   You can ignore it for now.
 
 - **The `data` directory** contains input data and related resources, described later in the course.
 
-- **The `solutions` directory** contains completed module files and a Part 2 solution that can serve as a starting point for Part 3.
+- **The `solutions` directory** contains completed workflow scripts and modules that result from each step of the course.
   They are intended to be used as a reference to check your work and troubleshoot any issues.
+  The Part 2 solution can be used as a starting point for Part 3.
 
 ## Readiness checklist
 
@@ -114,4 +113,4 @@ Think you're ready to dive in?
 
 If you can check all the boxes, you're good to go.
 
-**To continue to [Part 1: Method overview and manual testing](./01_method.md), click on the arrow in the bottom right corner of this page.**
+**To continue to [Part 1: Method overview](./01_method.md), click on the arrow in the bottom right corner of this page.**