Add util function to get terminal size

app/src/util/term.h

@@ -0,0 +1,21 @@
+#ifndef SC_TERM_H
+#define SC_TERM_H
+
+#include "common.h"
+
+#include <stdbool.h>
+
+/**
+ * Return the terminal dimensions
+ *
+ * Return false if the dimensions could not be retrieved.
+ *
+ * Otherwise, return true, and:
+ *  - if `rows` is not NULL, then the number of rows is written to `*rows`.
+ *  - if `columns` is not NULL, then the number of columns is written to
+ *    `*columns`.
+ */
+bool
+sc_term_get_size(unsigned *rows, unsigned *cols);
+
+#endif