fix few typos for the instruction/prompt files notes

Author: legomushroom

release-notes/v1_100.md

@@ -132,14 +132,14 @@ If a file edit in agent mode introduces new errors, agent mode can now detect th
 
 ### Prompt and instructions files
 
-We now distinguish between 'instructions' and 'prompt' files. They use the same fiele format but have separate file suffices and features. The purpose of the separation is to align with the existing custom instructions feature and make the UI more intuitive.
+We now distinguish between 'instructions' and 'prompt' files. They use the same file format but have separate file suffices and features. The purpose of the separation is to align with the existing custom instructions feature and make the UI more intuitive.
 
 **Instruction files** (aka custom instructions, rules) provide context to a request, typically describing code guidelines or specifying which framework to use.
 
 Instruction files use the `.instructions.md` file suffix. They can be located in your user data folder or in the workspace. The `setting(chat.instructionsFilesLocations)` setting lists the folders that contain the instruction files.
 
 Instructions files can be added manually or automatically to chat requests.
-- To add them manually, use the `Add Context ` button in the chat view and select `Instructions...`. Alternativly use the `Chat: Attach Instructions File...` command from the command palette. This brings aup a picker that lets you select existing instructions files or create a new one to attach.
+- To add them manually, use the `Add Context ` button in the chat view and select `Instructions...`. Alternatively use the `Chat: Attach Instructions File...` command from the command palette. This brings aup a picker that lets you select existing instructions files or create a new one to attach.
 - To have them added automatically, add the `applyTo` header to the instructions file. If a chat request contains a file that matches the given pattern, the instructions file will be attached.
 ````md
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@@ -240,7 +240,7 @@ When in [agent mode](vscode://GitHub.Copilot-Chat/chat?mode=agent), tool invocat
 
 ### Variable line heights
 
-It is now possible to define variable line heights on a monaco editor by setting the line height value in the `IModelDecorationOptions` type. If two line heights are set on a line, the maximum of the two will be used on the line. Please note that for simplicity for now, the line height is set only on the first line of the corresponding decoration range. In the following screen recording, lines 24 and 32 are rendered with a larger line height than the default line height. This work is not yet available to extensions, but will roll out after some more testing. 
+It is now possible to define variable line heights on a monaco editor by setting the line height value in the `IModelDecorationOptions` type. If two line heights are set on a line, the maximum of the two will be used on the line. Please note that for simplicity for now, the line height is set only on the first line of the corresponding decoration range. In the following screen recording, lines 24 and 32 are rendered with a larger line height than the default line height. This work is not yet available to extensions, but will roll out after some more testing.
 
 <video src="images/1_100/variable-line-heights.mp4" title="Variable line heights" autoplay loop controls muted></video>