Mention that the DAPR_INSTALL_DIR directory must already exist (#2410)

Signed-off-by: Jakub Kuczys <6032823+jack1142@users.noreply.github.com>

Co-authored-by: greenie-msft <56556602+greenie-msft@users.noreply.github.com>
Co-authored-by: Mark Fussell <markfussell@gmail.com>

daprdocs/content/en/getting-started/install-dapr-cli.md

@@ -31,7 +31,7 @@ wget -q https://raw.githubusercontent.com/dapr/cli/master/install/install.sh -O
 
 #### Install without `sudo`
 
-If you do not have access to the `sudo` command or your username is not in the `sudoers` file, you can install Dapr to an alternate directory via the `DAPR_INSTALL_DIR` environment variable.
+If you do not have access to the `sudo` command or your username is not in the `sudoers` file, you can install Dapr to an alternate directory via the `DAPR_INSTALL_DIR` environment variable. This directory must already exist and be accessible by the current user.
 
 ```bash
 wget -q https://raw.githubusercontent.com/dapr/cli/master/install/install.sh -O - | DAPR_INSTALL_DIR="$HOME/dapr" /bin/bash
@@ -96,7 +96,7 @@ arch -arm64 brew install dapr/tap/dapr-cli
 ```
 
 #### Install without `sudo`
-If you do not have access to the `sudo` command or your username is not in the `sudoers` file, you can install Dapr to an alternate directory via the `DAPR_INSTALL_DIR` environment variable.
+If you do not have access to the `sudo` command or your username is not in the `sudoers` file, you can install Dapr to an alternate directory via the `DAPR_INSTALL_DIR` environment variable. This directory must already exist and be accessible by the current user.
 
 ```bash
 curl -fsSL https://raw.githubusercontent.com/dapr/cli/master/install/install.sh | DAPR_INSTALL_DIR="$HOME/dapr" /bin/bash