Improves the description of the installation command (#12354)

- **Description:**

 Before: 
`
To install modules needed for the common LLM providers, run:
`

After:
`
To install modules needed for the common LLM providers, run the
following command. Please bear in mind that this command is exclusively
compatible with the `bash` shell:
`


> This is required for the user so that the user will know if this
command is compatible with `zsh` or not.

---------

Co-authored-by: Bagatur <baskaryan@gmail.com>

docs/docs/get_started/installation.mdx

@@ -19,26 +19,7 @@ import CodeBlock from "@theme/CodeBlock";
 
 This will install the bare minimum requirements of LangChain.
 A lot of the value of LangChain comes when integrating it with various model providers, datastores, etc.
-By default, the dependencies needed to do that are NOT installed.
-However, there are two other ways to install LangChain that do bring in those dependencies.
-
-To install modules needed for the common LLM providers, run:
-
-```bash
-pip install langchain[llms]
-```
-
-To install all modules needed for all integrations, run:
-
-```bash
-pip install langchain[all]
-```
-
-Note that if you are using `zsh`, you'll need to quote square brackets when passing them as an argument to a command, for example:
-
-```bash
-pip install 'langchain[all]'
-```
+By default, the dependencies needed to do that are NOT installed. You will need to install the dependencies for specific integrations separately.
 
 ## From source