Feature Request: document change to default context window in 0.8.13

[cbowdon]

Prerequisites

• I am running the latest code. Mention the version if possible as well.
• I carefully followed the README.md.
• I searched using keywords relevant to my issue to make sure that I am creating a new issue that is not already open (or closed).
• I reviewed the Discussions, and have a new and useful enhancement to share.

Feature Description

(Before I start: Llamafile is amazing, thank you all!)

It would be useful - saved me some head-scratching - if the change from the default context size being 512 for every model to being specific by the model was more visible, either in release notes or the README. I can understand why that change was made, but it confused me as to why when I upgraded from 0.8.12 to 0.8.13, models that used to run fine suddenly failed to start.

Motivation

I originally thought it was a bug in 0.8.13, because this command: ./llamafile-0.8.12 -m Meta-Llama-3.1-8B-Instruct.Q4_K_M.gguf works fine whereas ``./llamafile-0.8.13 -m Meta-Llama-3.1-8B-Instruct.Q4_K_M.gguf` gives an allocation error on my M1 MBP.

Specifying the context size with -c resolves the problem easily, and when I look closely at the logs I see that it's precisely because n_ctx is different now. I only wish that this solution was more discoverable. It didn't occur to me that the context size might have changed and I couldn't find any mention of it in the release notes. Hopefully this ticket itself will save some other people time.

Possible Implementation

No response