Add image commands

pptxhandler/v2/README.md

@@ -300,10 +300,18 @@ content, or add new content (like charts). Here are some common commands:
 
 ### Position
 
-- `top`: sets top (Y) position
-- `left`: sets left (X) position
-- `width`: sets width
-- `height`: sets height
+- `top`: sets top (Y) position in [length units](#length-units), e.g. `3 inches`
+- `left`: sets left (X) position in [length units](#length-units), e.g. `3 inches`
+- `width`: sets width in [length units](#length-units), e.g. `3 inches`
+- `height`: sets height in [length units](#length-units), e.g. `3 inches`
+
+TODO: Example
+
+### Image
+
+- `image`: set image of a picture to a file or URL, e.g. `new-pic.png` or `https://picsum.photos/200`. Retains aspect ratio, width and position. May change the height
+- `image-width`: sets width in [length units](#length-units), e.g. `3 inches`. Retains aspect ratio and position (top and left). May change the height
+- `image-height`: sets height in [length units](#length-units), e.g. `3 inches`. Retains aspect ratio and position (top and left). May change the width
 
 TODO: Example
 
@@ -407,13 +415,32 @@ rules:
       fill: colors[0]         # Python expression using "colors" as a variable. Returns "red"
 ```
 
-To specify an explicit value, use `{value: ...}` instead. For example:
+To specify a literal text value, use `f'...'` instead. For example:
+
+```yaml
+rules:
+  - Rectangle 1:
+      width: f'6 inches'      # Just set the width to 6 inches
+      fill: f'red'            # Just set the color to red
+```
+
+Values inside `{}` are evaluated as Python expressions in the context of data. For example:
+
+```yaml
+data:
+  sales: [40, 50, 60]
+rules:
+  - Rectangle 1:
+      text: f'Sales is {sum(sales)}'  # Returns 'Sales is 150'
+```
+
+You can also use `{value: ...}` instead of `f'...'`. For example:
 
 ```yaml
 rules:
   - Rectangle 1:
-      width: {value: 6}       # Just set the width to 6
-      fill: {value: red}      # Just set the color to red
+      width: {value: 6}           # Set the width to 6
+      fill: {value: [255, 0, 0]}  # Set the color to RGB(255, 0, 0)
 ```
 
 If your value is a string, it's formatted as a template. Values inside `{}` are evaluated as Python