add README.md

Author: Mryan2005

README.md

@@ -0,0 +1,85 @@
+# install the package
+
+firstly, you should add the following line to your `~/.m2/settings.xml` file:
+
+```xml
+    <activeProfiles>
+            <activeProfile>github</activeProfile>
+    </activeProfiles>
+    <profiles>
+        <profile>
+            <id>github</id>
+            <repositories>
+                <repository>
+                    <id>central</id>
+                    <url>https://repo1.maven.org/maven2</url>
+                </repository>
+                <repository>
+                    <id>github</id>
+                    <url>https://maven.pkg.github.com/Mryan2005/JavaPlusPlus</url>
+                    <snapshots>
+                        <enabled>true</enabled>
+                    </snapshots>
+                </repository>
+            </repositories>
+        </profile>
+    </profiles>
+    
+    <servers>
+        <server>
+            <id>github</id>
+            <username>Mryan2005</username>
+            <password>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</password>
+        </server>
+    </servers>
+```
+
+And then you will see the following code in your `./m2/settings.xml` file
+
+```xml
+<settings xmlns="http://maven.apache.org/SETTINGS/1.0.0"
+          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+          xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0 http://maven.apache.org/xsd/settings-1.0.0.xsd">
+    // ...
+    <activeProfiles>
+            <activeProfile>github</activeProfile>
+    </activeProfiles>
+    <profiles>
+        <profile>
+            <id>github</id>
+            <repositories>
+                <repository>
+                    <id>central</id>
+                    <url>https://repo1.maven.org/maven2</url>
+                </repository>
+                <repository>
+                    <id>github</id>
+                    <url>https://maven.pkg.github.com/Mryan2005/JavaPlusPlus</url>
+                    <snapshots>
+                        <enabled>true</enabled>
+                    </snapshots>
+                </repository>
+            </repositories>
+        </profile>
+    </profiles>
+    
+    <servers>
+        <server>
+            <id>github</id>
+            <username>Mryan2005</username>
+            <password>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</password>
+        </server>
+    </servers>
+    // ...
+</settings>
+```
+
+Then you can add the following code to your `pom.xml` file:
+
+```xml
+<dependency>
+  <groupId>top.mryan2005.javaplusplus</groupId>
+  <artifactId>javaplusplus</artifactId>
+  <version>1.0-SNAPSHOT</version>
+</dependency>
+```