Add PotentSulfurLM, as a followup to CinnabarLM!

Per https://huggingface.co/spaces/CompactAI-O/Tiny-ML-Leaderboard/discussions/5:

"Next LLM to add will be PotentSulfurLM 500K (https://huggingface.co/MihaiPopa-1/PotentSulfurLM-500K-Base)!

It's a LLM with 587K parameters. Trained on ~200M tokens, ~4x the amount used to train CinnabarLM 1.5M!
```bash
!lm_eval --model hf \
--model_args pretrained=MihaiPopa-1/PotentSulfurLM-500K-Base \
--tasks blimp,arc_easy,wikitext \
--device cuda \
--batch_size 1024 \
--output_path results/
```
gives:

| Tasks |Version|Filter|n-shot| Metric | | Value | |Stderr|
|------------------------------------------------------------|------:|------|-----:|---------------|---|---------:|---|------|
|blimp | 2|none | 0|acc |↑ | 0.5901|± |0.0017|
|arc_easy | 1|none | 0|acc |↑ | 0.2706|± |0.0091|
|wikitext | 2|none | 0|bits_per_byte |↓ | 2.6131|± | N/A|
"

index.html

@@ -302,6 +302,16 @@ const models = [
     tokens: '~30M',
     links: { card: 'https://huggingface.co/MihaiPopa-1/CinnabarLM-1.4M-Base' }
   },
+  { 
+    name: 'PotentSulfurLM 500K', 
+    org: 'mihaipopa', 
+    params: '587K',
+    blimp: 59.01, 
+    arc: 27.06, 
+    wiki: 2.613, 
+    tokens: '~200M',
+    links: { card: 'https://huggingface.co/MihaiPopa-1/PotentSulfurLM-500K-Base' }
+  },
   { 
     name: 'StorySupra-10M', 
     org: 'supralabs',