added description to alt attributes

Author: burhan-mustafa

Wireframe/README.html

@@ -12,7 +12,7 @@ <h1>README Files</h1>
     </header>
     <main>
       <article>
-        <img src="./images/readme.png" alt="">
+        <img src="./images/readme.png" alt="README file displayed on a laptop screen">
         <h2>What is the purpose of a README file? </h2>
         <p>
           A README file is used to give information so a user can ascertain key details of a program such as its function, how it works, how to set it up and general updates.

Wireframe/branch.html

@@ -12,7 +12,7 @@ <h1>Git Branches</h1>
     </header>
     <main>
       <article>
-        <img src="./images/branch.png" alt="">
+        <img src="./images/branch.png" alt="A computer screen showing a visual Git branch diagram">
         <h2>What is a branch in Git? </h2>
         <p>
           A branch in Git is a seperate workspace used to experiment or make changes without affecting the main project.

Wireframe/wireframe.html

@@ -12,7 +12,7 @@ <h1>Wireframes</h1>
     </header>
     <main>
       <article>
-        <img src="./images/wireframes.png" alt="">
+        <img src="./images/wireframes.png" alt="A paper website wireframe design on a desk">
         <h2>What is the purpose of a Wireframe?</h2>
         <p>
           A wireframe is used as a structural blueprint that allows a developer to envision how a project will look.