Fixed outdated doc (install.md) and help text in root Makefile

Makefile

@@ -239,9 +239,9 @@ help_client:
 	@echo "  xbuild_client       Cross-build $(BIN) for Linux, Windows, Darwin (OSX)"
 	@echo "                      Require the BIN variable which specifies which binary to"
 	@echo "                      cross-build: nexush or nexus-cli"
-	@echo "                      Require SERVER and optionally CERT (see below)"
+	@echo "                      Require SERVER and CERT (see below)"
 	@echo "  build_nexush        Build nexush for Linux/amd64; require the SERVER variable"
-	@echo "                      and optionally CERT (see below)"
+	@echo "                      and CERT (see below)"
 	@echo "  build_nexus-cli     Build nexus-cli for Linux/amd64; same as above"
 	@echo "  build_nexus-exam    Build nexus-exam for Linux/amd64; require CERT, SERVER"
 	@echo "                      EXAM_USER and EXAM_PWD. The last two define credentials"

docs/install.md

@@ -168,7 +168,7 @@ sudo apt-get install -y golang-go make libglfw3-dev libxcursor-dev libxinerama-d
 
 ## Building nexush and nexus-cli
 
-These two environment variables are required:
+These three environment variables are required:
 
 - `BIN`: must be set to either `nexush` or `nexus-cli` to indicate what client to build
 - `SERVER`: defines two things:
@@ -176,21 +176,14 @@ These two environment variables are required:
      - typically 127.0.0.1 for development
   1) nexus-server API port; must match the value defined in `config/server/nexus.conf`
      - 1077 by default
-
-The `CERT` environment variable is optional:
-- If defined, specifies the directory where resides the public certificate `ca-cert.pem` (typically `nexus-server/certs/`)
-  - in this case, it is embedded in the nexus client being built
-- If not defined, the nexus client being built won't embed a certificate
-  - in this case, the full path to the public certificate must be specified when executing the client via the environment variable `NEXUS_CERT`, e.g.:
-    ```
-    NEXUS_CERT=$HOME/nexus-server/certs/ca-cert.pem nexush janedoe@nexus.org
-    ```
+- `CERT`:
+  - specifies the public certificate (`ca-cert.pem`) to embed in the client
   
 Both nexush and nexus-cli clients are built for multiple OSes (Linux, Windows, Mac) and architectures (amd64, i386 and arm64).
 
 The line below builds nexush for all supported OSes and architectures, where the public certificate (`ca-cert.pem`) is located in `$HOME/nexus-server/certs` and the nexus' server ip is 10.0.2.15 and it listens to port 1077:
 ```sh
-make xbuild_client BIN=nexush CERT=$HOME/nexus-server/certs SERVER=10.0.2.15:1077
+make xbuild_client BIN=nexush CERT=$HOME/nexus-server/certs/ca-cert.pem SERVER=10.0.2.15:1077
 ```
 
 Below, we build nexus-cli for all supported OSes and architectures, without an embedded certificate, and the server's ip is 127.0.0.1 and it listens to port 1077:
@@ -230,16 +223,21 @@ build/
         └── nexush.exe
 ```
 
+Although the public certificate is embedded in the client, it is possible to override it at execution time through the `NEXUS_CERT` environment variable. For example:
+```sh
+NEXUS_CERT=$HOME/nexus-server/certs/ca-cert.pem nexush janedoe@nexus.org
+```
+
 ## Specifically building for Linux/amd64
 
-For this specific case, only `SERVER` and `CERT` environment variables are used, in a similar way to what is described in [Building nexush and nexus-cli](#building-nexush-and-nexus-cli).
+This is a specific case that builds a client only for Linux/amd64 platofrm. The required environment variables are the same as in [Building nexush and nexus-cli](#building-nexush-and-nexus-cli).
 
 To only build nexush for Linux/amd64:
 ```sh
-make build_nexush CERT=$HOME/nexus-server/certs SERVER=10.0.2.15:1077
+make build_nexush CERT=$HOME/nexus-server/certs/ca-cert.pem SERVER=10.0.2.15:1077
 ```
 
-If you're only interested in building nexus-cli for Linux/amd64 uses the `build_nexus-cli` target instead.
+Similarly, if you're only interested in building nexus-cli for Linux/amd64 uses the `build_nexus-cli` target instead.
 
 ## Specifically running nexush for Linux/amd64
 
@@ -270,7 +268,7 @@ Similarly to nexush and nexus-cli, nexus-exam requires `SERVER` and `CERT` envir
 
 Here is an example of how to build nexus-exam:
 ```sh
-make build_nexus-exam CERT=$HOME/nexus-server/certs SERVER=10.0.2.15:1077 EXAM_USER=exam@nexus.org EXAM_PWD='3k0%tjslk$g42'
+make build_nexus-exam CERT=$HOME/nexus-server/certs/ca-cert.pem SERVER=10.0.2.15:1077 EXAM_USER=exam@nexus.org EXAM_PWD='3k0%tjslk$g42'
 ```
 
 ## Running nexus-exam