doc: add a simple documentation (#91)

* added some parts of documentation

* Updatde documentation

Author: elolelo

documentation/index.html

@@ -0,0 +1,139 @@
+@import url("https://fonts.googleapis.com/css2?family=Poppins:wght@300;400;500;600&display=swap");
+
+* {
+  margin: 0;
+  padding: 0;
+  box-sizing: border-box;
+  font-family: "Poppins", sans-serif;
+}
+
+body {
+  display: block;
+  height: 100%;
+  width: 100%;
+  background: #f5f6fa;
+}
+
+#navbar {
+  position: fixed;
+  top: 0;
+  left: 0;
+  padding: 10px;
+  height: 100%;
+  min-width: 350px;
+  color: #ffffff;
+  border: none;
+  background-color: #174782;
+}
+
+#navbar header {
+  margin: 10px 0;
+  font-size: 28px;
+  font-weight: 500;
+  letter-spacing: 1px;
+  word-spacing: 5px;
+
+}
+
+#navbar ul {
+  height: 88%;
+  overflow-x: hidden;
+  overflow-y: auto;
+}
+
+#navbar li {
+  padding: 10px 20px;
+  list-style-type: none;
+}
+
+#navbar a {
+  font-size: 17px;
+  text-decoration: none;
+  color: #bdc3c9;
+}
+
+#main-doc {
+  margin-left: 350px;
+  padding: 100px 50px;
+  text-align: justify;
+}
+
+
+#main-doc p {
+  margin-top: 20px;
+}
+
+#main-doc li {
+  margin: 10px 50px;
+}
+
+code {
+  display: block;
+  padding: 20px;
+  line-height: 30px;
+  font-size: 15px;
+  font-weight: 500;
+  letter-spacing: 1px;
+  word-spacing: 5px;
+  color: #abb2bf;
+  border-radius: 12px;
+  background: #353a40;
+}
+
+.comment {
+  color: #5c6370;
+}
+
+.keyword {
+  color: #c678dd;
+}
+
+.string {
+  color: #98c379;
+}
+
+.number {
+  color: #d19a66;
+}
+
+.operator {
+  color: #56b6c2;
+}
+
+@media screen and (width < 800px) {
+  body {
+    display: flex;
+    justify-content: center;
+    align-items: center;
+    flex-direction: column;
+  }
+
+  #navbar {
+    position: relative;
+    width: 100%;
+    min-height: 860px;
+  }
+
+  #navbar header {
+    font-size: 20px;
+    text-align: center;
+    border-bottom: 2px solid #ffffff;
+    padding-bottom: 20px;
+  }
+
+  header{
+    text-decoration: underline;
+    color: #c678dd;
+    font-size:medium
+  }
+
+  #navbar li a {
+    font-size: 20px;
+    letter-spacing: 1px;
+    word-spacing: 2px;
+  }
+
+  #main-doc {
+    margin-left: 0;
+  }
+}