Nit: Language fix in README.md (#871)

* Nit: Language fix in README.md

Usage of "then" vs "than"

* update TS petstore samples

modules/openapi-generator/src/main/resources/typescript-angular/README.mustache

@@ -11,10 +11,10 @@ npm run build
 ### publishing
 
 {{#useNgPackagr}}
-First build the package than run ```npm publish dist``` (don't forget to specify the `dist` folder!)
+First build the package then run ```npm publish dist``` (don't forget to specify the `dist` folder!)
 {{/useNgPackagr}}
 {{^useNgPackagr}}
-First build the package than run ```npm publish```
+First build the package then run ```npm publish```
 {{/useNgPackagr}}
 
 ### consuming

samples/client/petstore/typescript-angular-v2/default/README.md

@@ -10,7 +10,7 @@ npm run build
 
 ### publishing
 
-First build the package than run ```npm publish```
+First build the package then run ```npm publish```
 
 ### consuming
 

samples/client/petstore/typescript-angular-v2/npm/README.md

@@ -10,7 +10,7 @@ npm run build
 
 ### publishing
 
-First build the package than run ```npm publish```
+First build the package then run ```npm publish```
 
 ### consuming
 

samples/client/petstore/typescript-angular-v2/with-interfaces/README.md

@@ -10,7 +10,7 @@ npm run build
 
 ### publishing
 
-First build the package than run ```npm publish```
+First build the package then run ```npm publish```
 
 ### consuming
 

samples/client/petstore/typescript-angular-v4.3/npm/README.md

@@ -10,7 +10,7 @@ npm run build
 
 ### publishing
 
-First build the package than run ```npm publish dist``` (don't forget to specify the `dist` folder!)
+First build the package then run ```npm publish dist``` (don't forget to specify the `dist` folder!)
 
 ### consuming
 

samples/client/petstore/typescript-angular-v4/npm/README.md

@@ -10,7 +10,7 @@ npm run build
 
 ### publishing
 
-First build the package than run ```npm publish dist``` (don't forget to specify the `dist` folder!)
+First build the package then run ```npm publish dist``` (don't forget to specify the `dist` folder!)
 
 ### consuming
 

samples/client/petstore/typescript-angular-v6-not-provided-in-root/builds/default/README.md

@@ -10,7 +10,7 @@ npm run build
 
 ### publishing
 
-First build the package than run ```npm publish```
+First build the package then run ```npm publish```
 
 ### consuming
 

samples/client/petstore/typescript-angular-v6-not-provided-in-root/builds/with-npm/README.md

@@ -10,7 +10,7 @@ npm run build
 
 ### publishing
 
-First build the package than run ```npm publish dist``` (don't forget to specify the `dist` folder!)
+First build the package then run ```npm publish dist``` (don't forget to specify the `dist` folder!)
 
 ### consuming
 

samples/client/petstore/typescript-angular-v6-provided-in-root/builds/default/README.md

@@ -10,7 +10,7 @@ npm run build
 
 ### publishing
 
-First build the package than run ```npm publish```
+First build the package then run ```npm publish```
 
 ### consuming
 

samples/client/petstore/typescript-angular-v6-provided-in-root/builds/with-npm/README.md

@@ -10,7 +10,7 @@ npm run build
 
 ### publishing
 
-First build the package than run ```npm publish dist``` (don't forget to specify the `dist` folder!)
+First build the package then run ```npm publish dist``` (don't forget to specify the `dist` folder!)
 
 ### consuming