docs: baked a lot of API docs

docs/API/os.md

@@ -27,4 +27,73 @@ The `os` namespace provides date, time, and clock functions.
 - `%Z` and `%z`: time zone name and UTC offset
 - `%%`: literal percent sign
 
-${spacelua.renderApiDocumentation("os")}
+<!--#lua spacelua.renderApiDocumentation("os") -->
+## os.clock
+
+`os.clock()`
+
+Returns a high-resolution elapsed time value in seconds.
+
+**Returns:**
+
+- `number` — Browser performance timer in seconds.
+
+## os.date
+
+`os.date(format?, timestamp?)`
+
+Formats a timestamp as a date string or date table, optionally in UTC.
+
+**Parameters:**
+
+- `format?` (`string`) — `strftime`-style format, `*t` for a table, and optional leading `!` for UTC.
+- `timestamp?` (`number`) — Unix timestamp; defaults to the current time.
+
+**Returns:**
+
+- `string|table` — Formatted date or date fields.
+
+**Example:**
+
+```lua
+print(os.date("%Y-%m-%d"))
+local utc = os.date("!*t")
+```
+
+## os.difftime
+
+`os.difftime(t2, t1)`
+
+Returns the difference in seconds from timestamp `t1` to `t2`.
+
+**Parameters:**
+
+- `t2` (`number`)
+- `t1` (`number`)
+
+**Returns:**
+
+- `number` — The value `t2 - t1` in seconds.
+
+## os.time
+
+`os.time(): integer`
+`os.time(dateTable): integer`
+
+Returns the current Unix timestamp or one built from a local date table.
+
+**Parameters:**
+
+- `dateTable?` (`table`) — Local date fields `year`, `month`, `day`, and optional `hour`, `min`, and `sec`.
+
+**Returns:**
+
+- `integer` — Seconds since the Unix epoch.
+
+**Example:**
+
+```lua
+local timestamp = os.time({year = 2020, month = 1, day = 1})
+```
+<!--/lua-->
+