lib/file: Clarify what the functions do, take cursor position into account for cut functions and add missing cut function

src/lib/file.hpp

@@ -45,6 +45,7 @@ class File {
         void close();
 
         // only applicable to read and edit modes
+        // moves the cursor to the right of the read section
         ErrorOr<uint8_t> readByte();
         ErrorOr<std::vector<uint8_t>> read(uint64_t bytes);
         // @SodaFountain (or whoever ends up implementing this):
@@ -57,20 +58,24 @@ class File {
         // only applicable to write, modify, append, and edit modes
         // in modify and edit modes, overwrite whatever is at the
         // cursor position if there is anything there
+        // moves the cursor to the right of the written section
         ErrorOrVoid writeByte(uint8_t byte);
         ErrorOrVoid write(std::vector<uint8_t> data);
         ErrorOrVoid writeString(tiny_utf8::string string);
 
         // only applicable to modify and edit modes
         // insert at cursor position and move other contents to the right
+        // moves the cursor to the right of the inserted section
         ErrorOrVoid insertByte(uint8_t byte);
         ErrorOrVoid insert(std::vector<uint8_t> data);
         ErrorOrVoid insertString(tiny_utf8::string string);
 
         // only applicable to edit mode
         // return the cut section, remove cut section from file
-        ErrorOr<std::vector<uint8_t>> cut(uint64_t start, uint64_t end);
-        ErrorOr<tiny_utf8::string> cutString(uint64_t start, uint64_t end);
+        // moves the cursor to the right of where it happened
+        ErrorOr<uint8_t> cutByte();
+        ErrorOr<std::vector<uint8_t>> cut(uint64_t length);
+        ErrorOr<tiny_utf8::string> cutString(uint64_t length);
 
         // modes:
         //  r (read)