fix some typos in the UML diagram

docs/interface-design/uml.tex

@@ -34,13 +34,14 @@
     \attribute{cursor: Cursor}
     \attribute{marker: Int}
     \attribute{active\_marker: Bool}
-
+    \attribute{font\_size: Int}
+    
     \operation{update(beg: Int, end:Int): void}
     \operation{insert(sign: SignSymb): void}
     \operation{modify(sign: SignSymb): void}
     \operation{remove\_left()}
     \operation{remove\_right()}
-    \operation{pop\_slice():void)}
+    \operation{pop\_slice():void}
     \operation{get\_slice(): SignSymb Array}
     \operation{align(x:Int, y:Int): Int}
     \operation{place(index: Int):(Int $\times$ Int)}
@@ -77,10 +78,10 @@
   \end{class}
   
   \begin{class}{SheetElement}{15,0}
-    \attribute{fontSize: Int}
+    \attribute{font\_size: Int}
     \attribute{design: Godot Data}
     \attribute{pos: Int$\times$Int}
-    \attribute{textPos: Int}
+    \attribute{text\_pos: Int}
     \operation{getters, setters}
   \end{class}