docs: document screenshot options and bindings

Author: Jaredl-Dev

SourceCode/EngineChanges/key_bindings.md

@@ -24,6 +24,8 @@ The command names are the names used by `CommandMap.ini` unless the entry is mar
 | `STEP_FRAME` | <kbd>O</kbd> | Observer | Advances one frame and pauses again in non-multiplayer games. |
 | `STEP_FRAME_ALT` | <kbd>Shift</kbd>+<kbd>O</kbd> | Everywhere | Alternate frame-step binding that can be used while playing. |
 | `SELECT_NEXT_IDLE_WORKER` | <kbd>Ctrl</kbd>+<kbd>I</kbd> | Game | Selects the next idle worker for the observed or local player. |
+| `TAKE_SCREENSHOT` | <kbd>F12</kbd> | Everywhere | Saves a JPEG screenshot. JPEG quality is controlled by [`JPEGQuality`](options_ini). |
+| `TAKE_SCREENSHOT_PNG` | <kbd>Ctrl</kbd>+<kbd>F12</kbd> | Everywhere | Saves a lossless PNG screenshot. |
 
 ## Default-Only Controls
 

SourceCode/EngineChanges/options_ini.md

@@ -13,6 +13,7 @@ Boolean values are written as `yes` or `no`; parsing is case-insensitive.
 | `TextureFilter` | `None`, `Point`, `Bilinear`, `Trilinear`, `Anisotropic` | `Bilinear` | Selects the global texture filtering mode. Invalid names fall back to `None`. |
 | `AnisotropyLevel` | Practical values are `2`, `4`, `8`, `16` | `2` | Selects anisotropic filtering level. Other integer values are clamped to `2` through `16` and rounded down to the highest supported power of two. |
 | `ResolutionFontAdjustment` | Non-negative number. `100` means 100%. | Unset | Overrides the `GlobalLanguage.ini` resolution font adjustment. Negative values or an absent key use the `GlobalLanguage.ini` setting. |
+| `JPEGQuality` | `1` through `100` | `80` | Controls JPEG screenshot quality. Values outside the range are clamped; PNG screenshots are unaffected. |
 
 ## Shell and UI