Update local_build.md

made some corrections to the steps.

Signed-off-by: Kersten Richter <kersten@riscv.org>

local_build.md

@@ -153,10 +153,15 @@ brew install nvm
 mkdir ~/.nvm
 ```
 
-open either ~/.bash_profile or ~/.zshrc (for macOS Catalina or later):
+open either ~/.bash_profile or ~/.zshrc (for macOS Catalina or later) in vim or nano.
+
+
+```cmd
+nano ~/.bash_profile
+```
 
 ```cmd
-vim ~./bash.profile
+vim ~/.zshrc
 ```
 
 Add the following lines to the profile:
@@ -172,6 +177,10 @@ Load the profile:
 source ~/.zshrc
 ```
 
+```cmd
+source ~/.bash_profile
+```
+
 Install the most recent node, node 15, and make node 15 the version you use:
 
 ```cmd
@@ -192,8 +201,6 @@ Check that wavedrom-cli is in the path (this should display the help):
 wavedrom-cli
 ```
 
-NOTE: It appears that Oracle JDK is also required for WaveDrom diagrams to work. You can find a link to the JDK below.
-
 For Windows:
 
 WARNING: We can guess that node 15 is required for Windows.