Add grammar.tex, shamelessly copying from Pixeled. But the grammar is not exactly as implemented here, must revise it.

.gitignore

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 .idea/
 target/
+out/

src/main/resources/docs/grammer.tex

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+%! Author = manuel
+%! Date = 24.03.24
+
+% Preamble
+\documentclass[11pt]{article}
+
+% Packages
+\usepackage{amsmath}
+
+% Document
+\begin{document}
+    \begin{align}
+    [\text{Prog}]
+        &\to [\text{Stmt}]^* \\
+        [\text{Stmt}] &\to
+        \begin{cases}
+            \text{exit}([\text{Expr}]); \\
+            \text{let}\ \text{ident} = [\text{Expr}]; \\
+            \text{ident} = \text{[Expr]}; \\
+            \text{if} ([\text{Expr}])[\text{Scope}]\text{[IfPred]}\\
+            [\text{Scope}]
+        \end{cases} \\
+        \text{[Scope]} &\to {[\text{Stmt}]^*} \\
+        \text{[IfPred]} &\to
+        \begin{cases}
+            \text{elif}(\text{[Expr]})\text{[Scope]}\text{[IfPred]} \\
+            \text{else}\text{[Scope]} \\
+            \epsilon
+        \end{cases} \\
+        [\text{Expr}] &\to
+        \begin{cases}
+        [\text{Term}]
+            \\
+            [\text{BinExpr}]
+        \end{cases} \\
+        [\text{BinExpr}] &\to
+        \begin{cases}
+            [\text{Expr}] \^\ [\text{Expr}] & \text{prec} = 3 \\
+            [\text{Expr}] * [\text{Expr}] & \text{prec} = 2 \\
+            [\text{Expr}] / [\text{Expr}] & \text{prec} = 2 \\
+            [\text{Expr}] \% [\text{Expr}] & \text{prec} = 2 \\
+            [\text{Expr}] + [\text{Expr}] & \text{prec} = 1 \\
+            [\text{Expr}] - [\text{Expr}] & \text{prec} = 1 \\
+        \end{cases} \\
+        [\text{Term}] &\to
+        \begin{cases}
+            \text{int\_lit} \\
+            \text{ident} \\
+            ([\text{Expr}])
+        \end{cases}
+    \end{align}
+\end{document}