Temporary: move static files into content

During migration, while we launch Redocly with -d content, the static
files need to be in content. Eventually, when we stop using -d, we need
to move the files again.

Previously:
/assets : static assets used by templates
/img : images used in documentation (mostly)

Now:
/content/static : static assets used by templates
/img : images used in documentation (mostly)

Eventually:
/static : static assets used by templates
/docs/img : images used in documentation

content/static/js/use-cases.js

@@ -0,0 +1,68 @@
+$(document).ready(() => {
+    //show these featured on load. 
+    const show_cats_arr = ["infrastructure", "developer_tooling"]
+
+    function refreshList() {
+
+        $("#use_case_companies_list .card-uses").hide()
+
+        for (const category of show_cats_arr) {
+            $(`#use_case_companies_list .card-uses.category_${category}`).show()  
+        } 
+
+        const featured_count = show_cats_arr.filter( (current) => {
+            return current == "infrastructure" || current == "developer_tooling"
+        })
+
+        const other_count = show_cats_arr.filter( (current) => {
+            if ( current !== "infrastructure" && current !== "developer_tooling" ){
+                return current
+            }
+        })
+
+        // update category counts
+        if (featured_count.length === 0) {
+            $(".featured_count").hide()
+        }else {
+            $(".featured_count").html(featured_count.length)
+            $(".featured_count").show()
+        }
+
+        if (other_count.length === 0) {
+            $(".other_count").hide()
+        }else{
+            $(".other_count").html(other_count.length)
+            $(".other_count").show()
+        }
+
+        if(show_cats_arr.length === 0) {
+            $(".total_count").hide()
+        }else {
+            $(".total_count").html(show_cats_arr.length)
+            $(".total_count").show()
+        }
+
+    }
+
+  $(".cat_checkbox input").change((event) => {
+
+    const lang = $(event.target).val()
+    const lang_checked = $(event.target).prop("checked")
+    
+    $(".input_"+lang).prop("checked", lang_checked)
+
+    if (lang_checked) {
+        if ( show_cats_arr.indexOf(lang) === -1){
+            show_cats_arr.push(lang)
+        }  
+    } else {
+        show_cats_arr.indexOf(lang) !== -1 && show_cats_arr.splice(show_cats_arr.indexOf(lang), 1)
+    }
+
+    // refresh all visible. 
+    refreshList()
+  })
+
+    // on first load show the featured cats. 
+    refreshList()
+})