chore(docs): Improve docs (#304)

README.md

@@ -1,14 +1,14 @@
 # Postee
 
-![Postee](postee.jpeg)
+![Postee](postee.png)
 
 ![Docker Pulls][docker-pull]
 [![Go Report Card][report-card-img]][report-card]
 ![](https://github.com/aquasecurity/postee/workflows/Go/badge.svg)
 [![License][license-img]][license]
 
 [download]: https://img.shields.io/github/downloads/aquasecurity/postee/total?logo=github
-[release-img]: https://img.shields.io/github/release/aquasecurity/postee.svg?logo=github
+[release-img]: https://img.shields.io/github/release/aquasecurity/postee.png?logo=github
 [release]: https://github.com/aquasecurity/postee/releases
 [docker-pull]: https://img.shields.io/docker/pulls/aquasec/postee?logo=docker&label=docker%20pulls%20%2F%20postee
 [go-doc-img]: https://godoc.org/github.com/aquasecurity/postee?status.svg

cfg-actions.yaml

@@ -33,7 +33,7 @@ outputs:
   type: exec
   enable: true
   env: ["MY_ENV_VAR=foo_bar_baz", "MY_KEY=secret"]     # Optional. Any environment variables to pass in
-  input-file: exec-test.sh                             # Required. Specify the path to the script to run
+  input-file: /tmp/exec-test.sh                        # Required. Specify the path to the script to run
 
 - name: my-http-get
   type: http
@@ -52,4 +52,4 @@ outputs:
   headers:                            # Optional. Headers to pass in for the request.
     "Foo": ["bar", "baz"]
   timeout: 10s                        # Optional. Timeout value in XX(s,m,h)
-  bodyFile: tracee.event.logs         # Optional. Body of the HTTP request
+  bodyFile: /tmp/tracee.event.logs    # Optional. Body of the HTTP request

outputs/exec.go

@@ -40,7 +40,7 @@ func (e *ExecClient) Send(m map[string]string) error {
 
 	var err error
 	if e.Output, err = cmd.CombinedOutput(); err != nil {
-		return fmt.Errorf("error while executing script: %w", err)
+		return fmt.Errorf("error while executing script: %w, output: %s", err, string(e.Output))
 	}
 	log.Println("execution output: ", "len: ", len(e.Output), "out: ", string(e.Output))
 	return nil

outputs/exec_test.go

@@ -70,7 +70,7 @@ input foo env var
 		}
 		require.EqualError(t, ec.Send(map[string]string{
 			"description": "foo bar baz",
-		}), "error while executing script: exit status 1")
+		}), "error while executing script: exit status 1, output: failure")
 	})
 
 }

ui/frontend/src/components/LoginForm.vue

@@ -1,6 +1,6 @@
 <template>
   <form class="form-signin text-center" @submit.prevent="doSubmit">
-    <img class="mb-2" src="/postee.jpeg" alt="" width="140" height="170">
+    <img class="mb-2" src="/postee.png" alt="" width="140" height="170">
     <h1 class="h3 mb-3 font-weight-normal">Please sign in</h1>
     <label for="username" class="sr-only">Username</label>
     <input