Only trim line breaks at the end of input file

The general trim() function trims at the file's start, too.
This is a problem when whitespace at the beginning of the
first line is essential (as in 2017, day 19's input).

Also: Add a line break in the Grid class for better debugging.

Author: rhaendel

src/main/kotlin/de/ronny_h/aoc/AdventOfCode.kt

@@ -18,7 +18,7 @@ abstract class AdventOfCode<T>(val year: Int, val day: Int) {
 
     fun readInput(): List<String> {
         val inputFile = "/$year/Day${paddedDay()}.txt"
-        return AdventOfCode::class.java.getResource(inputFile)?.readText()?.trim()?.lines()
+        return AdventOfCode::class.java.getResource(inputFile)?.readText()?.trimEnd('\n')?.lines()
             ?: error("The input file for day $day, year $year could not be found. Expected at '$inputFile' in the resources folder.")
     }
 

src/main/kotlin/de/ronny_h/aoc/extensions/grids/Grid.kt

@@ -61,7 +61,9 @@ abstract class Grid<T>(
     }
 
     protected fun initGrid(input: List<String>) = input.forEachIndexed { row, line ->
-        line.forEachIndexed { col, char -> grid[row][col] = char.toElementType() }
+        line.forEachIndexed { col, char ->
+            grid[row][col] = char.toElementType()
+        }
     }
 
     /**