The name Halstatt seems to mean Salt Town.
No, it means nothing. You shall not needlessly anglicize.
The name Hallstadt (not the two l letters) means Salt Town.
Or, actually "place". In a lot of location names of germanic origin "stadt" doesn't the current semantics, of being a town with > 10.000. More often than not it just means "place".
And "Hall" is an old term for salt. Many towns related to salt have it in their names, in many places of Germany and Austria. "Halle an der Saale" in Thüringen, Bad Reichenhall (Bayern), Hall im Tirol (Österreich), Schwäbisch-Hall (Baden-Württemberg) etc.
"Hall" is believed to be of celtic origin.
And the double l is important. German is a language where in the written form you look at the letters and you immediately see how it is spoken. A double vocal makes the speed slower, and a double consonant makes the speech faster. So "Halstadt" would be slow Hal (so more emphasize on the "a" instead), and "Hallstadt" would be a fast "Hall", similar in speed like the english "hell": little emphasize on the "a".
Hallstatt means salt stead - a place where you find salt.
Stadt (town) was derived from Statt - here's a good explanation of that: https://www.duden.de/sprachwissen/sprachratgeber/Stadt-Statt...