[docs] Minor fixes (#5369)

minor fixes

docs/source/en/using-diffusers/img2img.md

@@ -131,7 +131,7 @@ init_image = Image.open(BytesIO(response.content)).convert("RGB")
 prompt = "Astronaut in a jungle, cold color palette, muted colors, detailed, 8k"
 
 # pass prompt and image to pipeline
-image = pipeline(prompt, image=init_image, strength=).images[0]
+image = pipeline(prompt, image=init_image, strength=0.5).images[0]
 image
 ```
 

docs/source/en/using-diffusers/inpaint.md

@@ -176,7 +176,7 @@ image = pipeline(prompt=prompt, image=init_image, mask_image=mask_image, generat
 
 Image features - like quality and "creativity" - are dependent on pipeline parameters. Knowing what these parameters do is important for getting the results you want. Let's take a look at the most important parameters and see how changing them affects the output.
 
-## Strength
+### Strength
 
 `strength` is a measure of how much noise is added to the base image, which influences how similar the output is to the base image.
 
@@ -217,7 +217,7 @@ image = pipeline(prompt=prompt, image=init_image, mask_image=mask_image, strengt
   </div>
 </div>
 
-## Guidance scale
+### Guidance scale
 
 `guidance_scale` affects how aligned the text prompt and generated image are.