Move the library to the separate repository

PID.h

@@ -0,0 +1,40 @@
+/*
+ * This file is part of the libsidservo project.
+ * Copyright 2025 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <stddef.h>
+
+#include "sidservo.h"
+
+typedef struct {
+    PIDpar_t gain;      // PID gains
+    double prev_error;  // Previous error
+    double integral;    // Integral term
+    double *pidIarray;  // array for Integral
+    struct timespec prevT; // time of previous correction
+    size_t pidIarrSize; // it's size
+    size_t curIidx;     // and index of current element
+} PIDController_t;
+
+PIDController_t *pid_create(const PIDpar_t *gain, size_t Iarrsz);
+void pid_clear(PIDController_t *pid);
+void pid_delete(PIDController_t **pid);
+double pid_calculate(PIDController_t *pid, double error, double dt);
+
+mcc_errcodes_t  correct2(const coordval_pair_t *target);