fix install instruction (#4)

url kwarg is needed otherwise installing yields this error

ERROR: `https://github.com/svilupp/AIHelpMe.jl` is not a valid package name. Perhaps you meant `https://github.com/svilupp/AIHelpMe`
The argument appears to be a URL or path, perhaps you meant `Pkg.add(url="...")` or `Pkg.add(path="...")`.

README.md

@@ -20,7 +20,7 @@ To install AIHelpMe, use the Julia package manager and the address of the reposi
 
 ```julia
 using Pkg
-Pkg.add("https://github.com/svilupp/AIHelpMe.jl")
+Pkg.add(url="https://github.com/svilupp/AIHelpMe.jl")
 ```
 
 **Prerequisites:**
@@ -178,4 +178,4 @@ AIHelpMe is continuously evolving. Future updates may include:
 - Enhancement of the marginal information provided by the RAG context.
 - Expansion of content sources beyond docstrings, potentially including documentation sites and community resources like Discourse or Slack posts.
 
-Please note that this is merely a pre-release to gauge the interest in this project.
+Please note that this is merely a pre-release to gauge the interest in this project.